> That surprises me. Recently? And you've done that by transplanting the platters into a new drive? (Assume we wrecked the heads completely when we removed the platters)

Few years since the last time. I've done that by opening a damaged drive that didn't want to spin up, and "helping" the motor get it started. The first time I tried this was a long, long time ago, and I ran that drive for ~6 months open and exposed, but that time was certainly with far lower densities. I've not tried this with wrecked heads, but given I tried this just by connecting a drive, I'm unwilling to risk assuming damaging the heads is sufficient as well - maybe it is; it certainly would make it harder. I'll happily believe that I've just gotten lucky in getting data out this way, but the point is it's clearly possible whether or not it may be rare for it to work that well, and it's an unnecessary risk.

> Really? You've recovered data from part-broken platters that have been removed and scratched or partially shattered?

Scratches, yes.

Partly shattered I haven't tried; I haven't had a reason to. If you make sure every platter is shattered, then it might well be sufficient. I've yet to see someone enforce shattering plates - most attempts at drive destruction I see tends to be people who haven't even bothered opening the drive, but have just tried destroying it from the outside and ended up damaging PCBs etc. but nothing more (reality is that most IT department in smaller shops don't even have hex tools small enough to open a modern drive); I have never had reason to try to recover data from drives people have made serious attempts at physically destroying the platters properly on.

> Sure, but unless the CEO is going to inspect every drive destruction, you're trusting people have actually done the rest too. There's trust here somewhere.

That's true, but it is easier to enforce visual inspection of a physical object than to try to forensically verify that a drive has been digitally overwritten in a way that is actually meaningful. Of course at some point you have done enough.

More importantly, by insisting on a standard of visual inspection to confirm a drive is destroyed or severely damaged, you ensure the commercial value of the drive itself reduces the incentive to remove drives that may or may not yet have been properly wiped.

> You can usually see from the command output if it has.

Assuming the person doing the destruction cared enough to pay attention.

> If the firmware was compromised all bets are off anyway, the data's already been exfiltrated using spin speed modulation to transmit your data out as audio, as far as you know...

Or it hasn't, and someone replaced it exactly because it's a simple means of bypassing a non-physical destruction process and carry the drives out right in front of security even if someone else needs to sign off on the wipe. It may seem contrived, but replacing firmware is a well enough attack by now that is seems like a pointless risk.

To be clear, I'm not questioning that you can ensure you have wiped the data digitally if you do it yourself and take enough care. But I don't think that is a good basis for a company to set policies around, because it's too hard to enforce once you take into account potential malicious interference and/or profit potential.