Billion's a tricky number, because old billion and new billion are a few orders of magnitude away from each other. Going with the thousand million def and dividing by ten to get a year:

100,000,000 / (24 * 365)
= 11,415

313 million people in the US. Computing clusters of similar capability required to observe them all:

313,000,000 / (100,000,000 / (24 * 365))
= 27,418

Granted, better or worse depending on how much you want to look at of their lives. If people only film important events is that better or worse for you? If they film important events how does that shift the balance of evidence from what the video contains as compared to the mere fact that they filmed the event?

I think... I fear that in many ways what you're talking about - video processing aside - is already here. If I put my evil hat on for a minute:

Okay, we want to work out what someone buys, where she lives, what she wears, who she knows, where she goes...

Where's that information already written down?

• If she went into a store her phone probably pinged the wifi, whether or not she connected:

http://www.tomsguide.com/us/Wi-Fi-tracking-Nordstrom-Cisco-R...

• ANPR systems are already widely deployed, so that's anywhere she went in a car:

http://www.projectcensored.org/police-tracking-license-plate...

• Credit card companies keep records of your purchases, obviously.

• There, probably, are going to be pictures of her on facebook.

• Facebook can be easily mined for relationship details - most people don't set their pages to hide their friends lists, despite the fact they should.

• Your IP address and browser fingerprint is trivially trackable.

https://panopticlick.eff.org/

For comparison you need 32.7 bits to pick someone out of the world population. Doesn't make you uniquely trackable of itself but puts you in a fairly small group.

... And the topic and language someone chooses to write about online... well, I agree but I don't think you need particularly powerful computers to do that - and given that I suspect there's more powerful evidence out there I'd expect that only to be deployed against individuals of interest.

#

I don't think the big threat to privacy is more powerful computers. Though they certainly don't help, I think the damage in that sense was done with the first ANPR system. I think the big threat is networked databases that already exist and take much less effort to extract relatively strong evidence out of.

I've also got some reservations as to what you're talking about is comparable in complexity to just encoding the video for upload. I agree that that is processing, but the data's already structured in a known way and the transformations performed on it are relatively simple. The question to my mind here really does make Moores law the important thing. I know that youtube does try to check for copyrighted content - but equally they're not particularly good at it even there.

Unfortunately I can't really visualise exactly what you're talking about in my head in terms of what you want to do to the data - face-recognition would presumably be part of it, as would voice to text, and then you'd want to check that against databases of stored signatures. Possibly you could make the task vastly less complex by using other data around it to limit your database queries, but still. That's not a simple thing. Against individuals of interest, I could totally see it being done, but everyone seems very wasteful - I'm not sure how the small amounts of evidence I think you'd get would justify the costs unless costs became very low.

If we're looking at something like a 20 magnitude increase in computing power over the next fifty years or so, (and similar increases in access speed and so on,) then all those concerns just sort of vanish away into the sea of massive power. ^_^