Tired of Big Brother myths.. When a cellular is off, its off. Right? - Page 1
Forum section: electronics / general

author: Cliff Matthews
author_rank: Unknown
timestamp: March 07, 2017, 09:29:04 pm
content: I'm getting dragged into mythville kicking a screaming these days by family members. Has anyone measured power draw on a cell phone when it's off? These nuts say big brother can turn it back on..

author: MarkS
author_rank: Unknown
timestamp: March 07, 2017, 09:43:02 pm
content: It's plausible. The power button on all smartphones are just a soft power off. I could easily see that this would be possible with the right software. So long as the screen stays black, how would you know?

author: alexanderbrevig
author_rank: Frequent Contributor
timestamp: March 07, 2017, 09:43:58 pm
content: Couldn't you measure it?Also, here's the nuts i thought of when I saw deez sentences you wrote.[how do I embed a YT video!?] EDIT: simply by pasting the URL

author: bji900
author_rank: Contributor
timestamp: March 07, 2017, 09:44:55 pm
content: I would assume there is a base level of power that would be required to run the cellular modem. If you had battery access then you could measure the off power current. I am sure there is also a way to monitor the rf energy that the system gives off. However I am not an RF expert and not sure how that would be done.

author: alexanderbrevig
author_rank: Frequent Contributor
timestamp: March 07, 2017, 09:47:03 pm
content: Kickstart an RF shield that also serves as an over-unity, energy harvesting, fashionable and green protective cover.

author: Dubbie
author_rank: Unknown
timestamp: March 07, 2017, 09:55:39 pm
content: None of that vault 7 stuff is a myth.It's all technically possible, desirable (to the CIA) and with the monstrous budget the CIA has, why wouldn't you assume it has happened?

author: Cliff Matthews
author_rank: Unknown
timestamp: March 07, 2017, 10:14:01 pm
content: When I stated off, I didn't mean just being on standby (screen dark but radio on). The other stupid thing they push is that it's possible to listen to microphones on POTS phones even when they're hung-up. The hook-switch goes open when hung-up, so it's like the electrons would have to jump over double sets of contacts.. the only thing on the line is the ringer coupling capacitors and through that and 4000 ft. of low grade cable, they'd hear sweet zip.

author: Cliff Matthews
author_rank: Unknown
timestamp: March 07, 2017, 10:26:45 pm
content: Suppose I could wedge-in at the battery foil strips over scotch tape and use DMM to measure uA.. (Not that I have anything to hide or Hyde)

author: moz
author_rank: Regular Contributor
timestamp: March 07, 2017, 10:41:01 pm
content: Yep, measuring is the only way. But you'd need to somehow know when the phone was likely to be in "snoop" mode otherwise you'd just be detecting the normal standby power draw. I dunno about iPhones, but with Android you can do quite fun stuff on a rooted phone. And I have read some scary stuff about the insecurity of the basic radio gear (which also has significant software components), making me suspect that it might even be possible to hack most phones out from under the GUI-level OS.FWIW I have seen phones that will flatten the battery in a couple of weeks when off, presumably because they draw far too much standby power (to keep the RTC alive?) You learn these things when bushwalking or otherwise going off net for long periods... you get to the end of the track and someone whines that their iFone isn't turning on.The obvious solution is to buy a phone with a removable battery. And remove it when you want the phone to be "off, no, really, seriously, off means off" off.

author: timb
author_rank: Super Contributor
timestamp: March 08, 2017, 01:35:00 am
content: Quote from: Cliff Matthews on March 07, 2017, 10:14:01 pmEven off mode isn't off. The processor and baseband radio are still active, just in deep sleep mode. Generally they periodically wake up and poll the power button status (or use a wake capable GPIO pin as an interrupt). Since that's the case, it wouldn't take much to change the baseband radio's firmware to connect to the network briefly during these wake up intervals.In fact, this has been done years ago, even on non-smart phones. The only way to assure the phone is off is to buy one with a removable battery and take it out when you want to make sure it's actually off!As for POTS phones, sure a normal old school bell-ringer and carbon microphone phone would be secure when hung up, but there might be some possibility for hacking digital cordless phones or digital corded speaker phones so that they don't actually disconnect the line.The CIA also used to have bugs that were essentially tiny electret microphones that could be inserted into a phone jack and would constantly listen and transmit across the phone line (which was tapped).

author: Silveruser
author_rank: Regular Contributor
timestamp: March 08, 2017, 02:41:35 am
content: Quote from: Cliff Matthews on March 07, 2017, 10:14:01 pmSome old fashion POTs phones left the ear piece in circuit and yes it could serve as a microphone. Have you ever had to rewire a secure phone with a couple guards with auto weapons at ready? Previous tech made a wiring mistake, security sweep found it a few months later.

author: Cliff Matthews
author_rank: Unknown
timestamp: March 08, 2017, 03:12:30 am
content: I've taken apart myriads of POTS devices over many years and never observed anything that would allow listening over an open Hi-z loop (several thousand ohms, compared to 900 ohm sets). Even electronic sets, cordless DECT-6 et al.. still have a double pole relay to connect to the tip and ring. Some of my knowledge goes back to ISDN techwork for Infotron NJ in the 80's and Intel-Dial-logic NJ in the 90's, so I'm not saying I'm up-to-date or it can't be done, but the antiquated "outside plant wiring" is a major hurdle to overcome. I still install and program Nortel/Lucent PBX stuff every now and then.As for freq-hopping DECT-6 listening around my house, sure, I be they can do it. But my secrets are worth nothing (just another old-fart worried about sending my sons out to a world one day where few value respect anymore). Cheers all!

author: Brumby
author_rank: Unknown
timestamp: March 08, 2017, 03:49:31 am
content: I am a fan of "off" meaning "OFF". I like that my android phone allows me to remove the battery - and that ability is important to me.Quote from: Silveruser on March 08, 2017, 02:41:35 amNo.The closest I've ever come was on the deck of the Missouri when she visited Sydney in 1986. There were armed Marines up in the superstructure - and they weren't waving.

author: mtdoc
author_rank: Super Contributor
timestamp: March 08, 2017, 03:56:41 am
content: Bunny Huang takes this issue seriously and has been working with Edward Snowden on a hardware solution for journalists to use so their phone's GPS cannot be used to track them when it is in "airplane mode" (or perhaps even "off" ). He'spublished a paperon it.He discussed it on a recent Amp Hour episode and more extensively on a recent Adafruit "ask an engineer" episode. Pretty damn awesome if you ask me.

author: CJay
author_rank: Super Contributor
timestamp: March 08, 2017, 05:35:31 am
content: While I'm not denying the fact tht a lot of the folk jumping up and down screaming vindication are outright tinfoil nutjobs, this has been possible for some time, even before the current Android/iPhone/Winmobile devices.The best and most reliable way to ensure a mobile is off is to remove the battery.If you can.

author: jonovid
author_rank: Super Contributor
timestamp: March 08, 2017, 05:58:57 am
content: QuoteIf you can. ?place in a sound proof faraday cagealso can save your but from spontaneous combustion by fire-prone phones.as for tinfoil on your head its true Project MK-Ultra this has been possible for some timethe CIA's mind control program – is the code name given to a program of experiments on human subjects,at times illegal, designed and undertaken by the United States Central Intelligence Agency.may also be used by some news media, as part of a disinformation war too hide wikileaks & other leaks of truthyes modified phones do get used to kill human subjects. 007 style with tiny chips of c4

author: moz
author_rank: Regular Contributor
timestamp: March 08, 2017, 06:34:27 am
content: Quote from: CJay on March 08, 2017, 05:35:31 amGive me a big enough hammer and I can get the battery out of just about anything.

author: CJay
author_rank: Super Contributor
timestamp: March 08, 2017, 08:16:54 am
content: Whoah...*wanders away to safe distance, quietly, but maintaining eye contact*

author: Kalvin
author_rank: Super Contributor
timestamp: March 08, 2017, 08:23:01 am
content: Just make a wide bandwidth power detector and place it close to the phone's antenna. It should detect any radio activity whatsoever.

author: EEVblog
author_rank: Unknown
timestamp: March 08, 2017, 08:31:42 am
content: Bunnie and Edward Snowden have teamed up to make a phone case cover that tells you if you phone is secretly transmitting.

author: Red Squirrel
author_rank: Super Contributor
timestamp: March 08, 2017, 09:37:06 am
content: I have a new philosophy about this kind of stuff. If it's theoretically possible and feasible... it's probably happening. Or it will. So anything you can think of "could the government..." the answer is most likely yes. Pretty much can't trust anything and have to question everything. In the case of a phone, there could easily be a deep sleep mode but it still listens for a certain RF pattern. Simply listening does not require much power. If the government wanted to wake up phones that are turned off. (ex: at the border) they could have a transmitter that sends that specific wakeup packet. The phone would wake, but not turn on the screen, but it would also turn on a backdoor, so they can wirelessly connect to the file system and just get what they want. It could even be a separate embedded OS than your main one. This is theoretical possible and would not really be that complex or advanced.Smart TVs are another example, the minute the allegations came out about them having a mic I immediately figured that probably means the government can listen to people. Most people would say that's "tin foil hat" way of thinking. Well if you watch the news recently turns out the CIA was indeed using this.Honestly this is one of the things that got me interested in electronics. 1: I can perhaps analyze a device and try to find anything fishy or 2: design my own stuff. Home automation for example. I don't trust consumer home automation stuff with a 39.5 foot pole.The issue is all this is still speculations though. I think we need more experts to actually analyze this stuff and try to reverse engineer it.

author: tautech
author_rank: Super Contributor
timestamp: March 08, 2017, 09:40:56 am
content: Does the "Find my iPhone" work when it's asleep or off ?

author: SingedFingers
author_rank: Frequent Contributor
timestamp: March 08, 2017, 10:09:35 am
content: The annoying thing about all this is I work a large proportion of the time in the security side of the IT trade and I have had the piss taken out of me many times in the past for suggesting this sort of stuff is exactly what is happening.With respect to devices, the rules are simple, derived from when I was working at a defence contractor:1. If you don't control the hardware, you don't control the device.2. If you don't control the software, you don't control the device.3. If you don't control the network, you don't control the device.4. If you don't control access to the device, you don't control the device.Which is one reason you find on my bench a neat little analogue and basic digital haven away from this side of the universe. Not a computer or network in sight. I can disconnect from any thoughts on the matter.

author: CJay
author_rank: Super Contributor
timestamp: March 08, 2017, 11:17:41 am
content: Quote from: SingedFingers on March 08, 2017, 10:09:35 amAccompanied, I imagine, by comments similar to 'yeah, but they wouldn't bother', 'they wouldn't be allowed to' and the classic, makes me boil, 'why are you bothered if you've nothing to hide you've nothing to fear'.It's a simple fact of life that if there is a possible way to gain an advantage then someone will exploit it, they will certainly find it and it's almost guaranteed that it will leak or someone else will find it.Hell the only way to guarantee your hardware is secure is to build it yourself and I mean from etching the silicon upwards because it's been the subject of many fairly believable rumours that there are chips out there with state sponsored backdoors too.I may not be a tinfoiler but I am healthily cynical about promises of privacy and security.

author: SingedFingers
author_rank: Frequent Contributor
timestamp: March 08, 2017, 11:40:21 am
content: It's actually worse if you ask me: "yeah we know, but whatever. We can't win against a state level actor". Bad attitude IMHO.

author: donotdespisethesnake
author_rank: Super Contributor
timestamp: March 08, 2017, 01:20:44 pm
content: Yes, there's a lot of BS about what the letter agencies can do with electronic devices. I read some recently in a Guardian article, which ironically was trying to explain why old fashioned "wire taps" were no longer used. I have seen people claim phone can be tracked even without battery, that's impossible. I have worked on mobile phone software, so I know how it works.People talk of "GPS tracking", but the GPS signal is receive only. It requires normal radio comms to transmit location (3G, wifi etc).Normally, when a phone is "off", the radio is shutdown completely, but the CPU is in a low power standby.The way the exploit works is malware that presents a "fake" off state, so the users thinks it is off (dark screen etc), but actually the CPU is still running in normal mode, and the phone can transmit/receive. When in the fake off state, the phone obviously uses a lot more power, which can be a giveaway.Installing the malware requires getting the user to download something, but this can be achieved by setting up a compromised cell tower, and pushing a "software update" required message to the phone. Clearly, there is a lot of work involved, but there is nothing impossible. The "fake off" hack is apparently also used on Samsung smart tvs.Never underestimate old fashioned hacks as well, just send the victim a free USB stick disguised as a promotion gimmick and wait for them to plug it in...

author: hammy
author_rank: Unknown
timestamp: March 08, 2017, 02:04:23 pm
content: It's common sense. This is all possible since more than 10 years.Quotehttps://www.techdirt.com/articles/20130723/12395923907/even-powering-down-cell-phone-cant-keep-nsa-tracking-its-location.shtmlSilent SMS:Quotehttps://en.wikipedia.org/wiki/Short_Message_Service#Silent_SMSQuotehttps://en.wikipedia.org/wiki/Cellphone_surveillanceQuotehttp://www.washingtonsblog.com/2013/06/the-single-most-important-step-to-protect-yourself-from-government-spying.htmlQuotehttp://money.cnn.com/2014/06/06/technology/security/nsa-turn-on-phone/https://www.wired.com/2014/06/nsa-bug-iphone/

author: Bud
author_rank: Super Contributor
timestamp: March 08, 2017, 05:13:35 pm
content: Define "power off" for the conversation to be meaningful

author: Cliff Matthews
author_rank: Unknown
timestamp: March 08, 2017, 05:29:31 pm
content: Didn't think I had to on this forum, but I did in #6. But ass-umption's, being what some they are, say battery removal (upsetting RTC) will stop "ghost in the box" wake-up's... It's like all the mfg's are hiding sneaky things from us... hidden from all, except the really secret EE's (like Dave).

author: CJay
author_rank: Super Contributor
timestamp: March 08, 2017, 06:50:01 pm
content: Quote from: Cliff Matthews on March 08, 2017, 05:29:31 pmYeah, that'd do it, except for RFID tracking I guess which could be added to any device just with a stick on patch (it's even a factory fit option on enterprise laptops from some manufacturers for asset management and anti theft)

author: hammy
author_rank: Unknown
timestamp: March 08, 2017, 09:03:21 pm
content: Here is a good summary from the Electronic Frontier Foundation:https://ssd.eff.org/en/module/problem-mobile-phones

author: fubar.gr
author_rank: Unknown
timestamp: March 08, 2017, 09:58:11 pm
content: Mexican drug lords have found a solution to this problem.They've built their very own private encrypted cell tower networkhttp://www.businessinsider.com/mexican-drug-cartels-have-built-their-own-national-radio-system-to-communicate-wih-members-2011-12

author: Halcyon
author_rank: Unknown
timestamp: March 08, 2017, 10:14:15 pm
content: Quote from: donotdespisethesnake on March 08, 2017, 01:20:44 pmSome handsets allow such tools to be loaded via the data port without knowing the users password. From there, data can be downloaded. Obviously this means physical access to the device is needed.

author: james_s
author_rank: Super Contributor
timestamp: March 08, 2017, 10:23:29 pm
content: Quote from: timb on March 08, 2017, 01:35:00 amI miss the old analog cordless phones. When I was a teenager I used to have the frequencies programmed into a scanner and often had it on in the background when we lived in an apartment. Never did anything nefarious with the information heard, it was just just fun. The analog cellphones were easy to listen in on too, the cellular companies lobbied to make it illegal to listen and required those frequencies to be locked out on scanners but it was an un-enforceable law. I've worked on a number of scanners and I've yet to encounter a Pro-2004, 2005 or 2006 that didn't have the cellular mod done.My attitude on the matter has always been if you don't want me to pick up your transmission, either encrypt it or keep your radio waves off my property.

author: senso
author_rank: Frequent Contributor
timestamp: March 09, 2017, 01:00:27 am
content: Quote from: EEVblog on March 08, 2017, 08:31:42 amHe could just get some of those old stickers with leds from the nokia3310 times, everybody and their cousing had some heart shapped thing that would blink like a christmas tree glued on the back of the phone, everytime you received/sent a message or receive/made a call..Even old electronics magazines had articles about that using old germanium diodes..As far as I know, the baseband as direct access to all system RAM and ROM, so yes, the phone can and will be listening to anything that is needed to know..

author: vk6zgo
author_rank: Super Contributor
timestamp: March 09, 2017, 01:40:57 am
content: If you are really paranoid, after turning off the phone, get an old 500g instant coffeecan, & stick the thing in that.Or just put the phone in the fridge.

author: Red Squirrel
author_rank: Super Contributor
timestamp: March 09, 2017, 01:43:17 am
content: Quote from: donotdespisethesnake on March 08, 2017, 01:20:44 pmI'm curious how does this work exactly? I figured the updates came from the software vendor, ex: Google or Apple. So when the phone needs an update it's contacting their servers. It might be using the cell towers if it's not on wifi, but the cell tower is just a carrier. Or are they actually injecting packets into the data stream to fake being the google server? If you always update through your wifi you should be safe from this right? Though that does beg the question what stops the government from injecting packets into regular internet streams too. So you download a linux distro from a trusted site, but you're actually getting a backdoored one without realizing because the government did something to your connection and you're actually downloading from another server.

author: SingedFingers
author_rank: Frequent Contributor
timestamp: March 09, 2017, 09:26:01 am
content: I know someone who worked in the billing side of things and the individual cell tower infrastructure, billing equipment, routing and distribution kit is compromised on a regular basis. He actually quit the job eventually as no one actually gave much of a shit. Don't forget that nice little Chinese companies like Huawei are right in there as the lowest bidder:https://en.wikipedia.org/wiki/Huawei#Security_concerns

author: woodchips
author_rank: Frequent Contributor
timestamp: March 09, 2017, 09:41:26 am
content: Any response to tautech's comment?Why not run the phone until the battery is flat, when you want to use it then plug a charging lead in. A flat battery is the same as a missing one.

author: CJay
author_rank: Super Contributor
timestamp: March 09, 2017, 09:59:44 am
content: Quote from: fubar.gr on March 08, 2017, 09:58:11 pmYou don't need to be a drug cartel to do this, it's been done at some of the hacker camps/conferences, the kit turns up on eBay for not much money.

author: CJay
author_rank: Super Contributor
timestamp: March 09, 2017, 10:03:47 am
content: Quote from: woodchips on March 09, 2017, 09:41:26 amBecause I want to be able to use my phone and the battery life is such that running it flat takes time, it's also not necessarily possible, some Android phones go into a kind of 'sleep' state when they shut down for low battery (HTC one and Desire are ones I have experience of), only when the battery is truly flat or removed have they actually fully powered off.

author: dmills
author_rank: Super Contributor
timestamp: March 09, 2017, 01:09:39 pm
content: Quote from: CJay on March 09, 2017, 09:59:44 amYep, the CCC do this routinely at Congress, with thousands of GSM client devices on the network.The thing is quite a lot of the useful intel can be obtained remotely without having to hack the phone, rough location for example is inherent in how the cell phone system works and anyone with a connection to the SS7 network (The out of band signalling network used by a teleco to setup and tear down calls) can obtain this information given the IMSI, which you can get with another SS7 query to the phones home network.For more accurate location information, you can leverage the emergency location stuff which has a horribly broken security model (Basically your request has to have an origin that matches an emergency call handling centre, but the reply address is a separate field....).SS7 is an old network designed back when telecoms were typically country wide monolithic entities that could be trusted to have grown ups in charge of the infrastructure, it deals poorly with loads of little companies playing in that space, and the complete lack of security is just the start of it.My working assumption has always been that a "Smart TV" is basically a Telescreen connected to anyone who wanted it badly enough.73 Dan.

author: timb
author_rank: Super Contributor
timestamp: March 09, 2017, 02:32:18 pm
content: Quote from: Red Squirrel on March 09, 2017, 01:43:17 amThere are also "Carrier Updates" pushed out by each carrier that are essentially lists of cell tower ids, routing information, etc. There are some known ways to exploit this on certain smartphones, causing the phone to run executable code.There is also the possibility of a compromised cell tower redirecting Android/iOS update checks from the official Google/Apple servers to compromised ones with hacked firmware full of backdoors. (Though that actually wouldn't work on iOS, since that will only update when plugged in and on WiFi.)

author: senso
author_rank: Frequent Contributor
timestamp: March 09, 2017, 03:13:26 pm
content: Quote from: Red Squirrel on March 09, 2017, 01:43:17 amBasically, OTA(over the air) updates to every piece of crap based on Android, because your provider likes to give you their custom flavour of last year Android, and because you are just another non tech savy person you just receive the update when the provider releases it(if ever).

author: Neganur
author_rank: Unknown
timestamp: March 09, 2017, 03:31:47 pm
content: Some of the paranoia makes me wonder if EE's don't read the manual of the components they use to develop circuits.DFU is not a secret tool put into cell phones, it's a tool of the uC to load firmware.Deep sleep is also nothing bad, yet being labeled as if the phone "never really turns off" (just like any other standby enabled TV etc?). Compared to older phone generations booting just takes too long. Old phones also don't poll the on/off button. There is a power management chip that switches the power rails to other parts of the phone. Modern phones have it all integrated into one chip.Secret SMS lol, read the GSM specification...it's not a thing the manufacturer secretly builds into the phone.There is a lot of communication between the phone and tower just to make sure the service works.I fully understand that not everyone can know about technology, but to then be upset about your own ignorance ... and there are many more things a phone can do that you didn't know about. Just that those are maybe not capable of generating scandalous news.It ofc sucks that you can't remove the battery from some modern phones. And well, modern software makes those phones very powerful - also for things they were not meant to do.Just buy a phone that lets you remove the battery if you want it off :|Anyway, I did not mean anyone in particular. I guess I am ranting. I also do not agree with intelligence (ab)using technology simply because it is so difficult to control the information - it is too easy for a government to change their views (a new president and similar) and use the formerly innocent data to use it against a minority of people (religion, political background, sexual preference etc).

author: CatalinaWOW
author_rank: Super Contributor
timestamp: March 09, 2017, 04:14:37 pm
content: Tautech and SingedFingers in posts 21 and 22 have given very succinct and complete responses to this. Everything else is just icing on the cake.

author: David Hess
author_rank: Super Contributor
timestamp: March 10, 2017, 03:49:53 am
content: Quote from: EEVblog on March 08, 2017, 08:31:42 amThat will not necessarily be helpful.Having the phone access the cell network while in bug mode would be very wasteful of operating time and would be more likely to be noticed compared to having it passively record and then transmit once the user turns it on to use it at which point the user will be expecting it to transmit.

author: Housedad
author_rank: Frequent Contributor
timestamp: March 10, 2017, 04:06:33 am
content: What's wrong with my tinfoil hat?

author: David Hess
author_rank: Super Contributor
timestamp: March 10, 2017, 04:29:36 am
content: Quote from: Housedad on March 10, 2017, 04:06:33 amThe only thing various leaks and court cases over the past few years have convinced me of is that I was not paranoid enough.

author: mtdoc
author_rank: Super Contributor
timestamp: March 10, 2017, 04:44:55 am
content: Quote from: David Hess on March 10, 2017, 03:49:53 amI believe the main purpose of the bunnie/Snowden device is to make the phone holder aware if GPS tracking is occuring when the device is "airplane mode" , not to listen in on conversations which I would think they assume is going to happen anyways. Knowing the location of a journalists cell phone can literally have deadly consequences.Read the link to bunnie's paper I posted earlier or listen to the Amp Hour or Adafruit interviews and it will be more clear.

author: CJay
author_rank: Super Contributor
timestamp: March 10, 2017, 07:33:11 am
content: Quote from: Neganur on March 09, 2017, 03:31:47 pmNever said it was a bad thing, just an illustration of the states a smartphone goes into when people think it's 'off' but still has a battery installed.Still comes down to 'take the battery out' if you're worried about what the phone is up to.I doubt any EE is knowledgable enough to know what every piece of electronic technology or chip does, but collective knowledge is incredibly powerful.

author: R005T3r
author_rank: Frequent Contributor
timestamp: March 10, 2017, 09:49:03 am
content: Quote from: alexanderbrevig on March 07, 2017, 09:47:03 pmyou mean this:

author: Galenbo
author_rank: Super Contributor
timestamp: March 10, 2017, 11:19:50 am
content: Quote from: james_s on March 08, 2017, 10:23:29 pmI remember the times I frequented CB/27mhz friends, one of them modified a cheap AM/FM radio to capture those analog communications.

author: David Hess
author_rank: Super Contributor
timestamp: March 10, 2017, 03:32:16 pm
content: Quote from: mtdoc on March 10, 2017, 04:44:55 amAw, what they did is a lot more sophisticated but it is more than just a phone case and requires hardware modifications to the phone.It will be interesting in the future when someone does this and catches a compromised phone which can then be analyzed.

author: bingo600
author_rank: Super Contributor
timestamp: March 10, 2017, 04:06:58 pm
content: This is supposed to be able to "Kill RF signals"http://www.ebay.com/itm/182062293897Make a purse/pocket (remember overlapping seems) , put the pone in the purse.And i should be unable to leak/get RF signals/Bingo

author: David Hess
author_rank: Super Contributor
timestamp: March 10, 2017, 04:23:34 pm
content: Quote from: bingo600 on March 10, 2017, 04:06:58 pmSeams have to do more than overlap. If they lack a continuous conductive connection, then they become a slot antenna which is why they make finger stock and abrasive metal gaskets to join seams in RF enclosures. It would also be nice to be able to use the phone.Microwave ovens operate at 2.4 GHz where the wavelength is short enough that the door geometry can be used to make a selective RF choke and no conductive seam is required but older microwave ovens that operated at 900 MHz could not do this; the door would have been too large. So instead they used finger stock to make a continuous conductive seam. Unfortunately this did not work out well in practice because the exposed finger stock would get bent up, food stuck to it, etc.

author: HAL-42b
author_rank: Frequent Contributor
timestamp: March 10, 2017, 05:30:14 pm
content: I wonder why these are so popular...I mean, even Obama likes doing some EMC testing during his lunch breaks...

author: rrinker
author_rank: Super Contributor
timestamp: March 10, 2017, 08:45:56 pm
content: Gets in Faraday Cage then uses Cisco IP phone which has an ethernet cable that SURELY extends outside that cage to a switch somewhere. Brilliant.

author: HAL-42b
author_rank: Frequent Contributor
timestamp: March 10, 2017, 09:40:57 pm
content: Looks like it but I'm sure it has been gutted and some modern equivalent to the STU-III crypto has been installed inside.http://www.cryptomuseum.com/crypto/motorola/sectel/index.htmYou can trust that a government hell bent on spying on everyone, everywhere, all the time, has this shit figured out.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: March 11, 2017, 12:04:57 am
content: Quote from: HAL-42b on March 10, 2017, 09:40:57 pmSomewhere in government, maybe multiple somewheres there are people who have figured this shit out. Whether they share that information with the White House, and whether those in the White House listen is a totally different story.