Re: You can get it back
the only way to defeat them is to shred the drive, and even then you'd better dump the pieces in different places 'cause if they get hold of enough pieces they can still get data.
.. which was the second argument we have against getting our own shredder.
Someone's got an overactive paranoia mode in their imagination.
So the shredder rips each platter into what, would 10,000 bits be reasonable? For a 2 platter drive there's 20,000 bits. Being a mechanical shredding process, there is also going to be some "dust" that once was part of the platters, but is not really part of the 10,000 bits per platter.
To reassemble the data on the drive they need to rebuild the platters. To do that they have to get every bit (physical chunk) into the right place, and the right way up. But where bits cracked and dust flaked off, there will be more bits that are lost. Finding and reassembling dust particles is impossible.
Another issue is the mechanism of the shredder, the very strong magnets in the drive, and the movement of bits of the platters as they separate from each other - all of these would also create magnetic fields within the fragments that could flip bits.
So even if they could get all the bits together, separated out from platter/drive electronics/case/etc, there's little chance anyone would have the resources to rebuild the platters.
And even if the platters could be rebuilt, there is 0 chance of actually getting the data off it.
A 3-pass secure wipe is plenty, but if you do wish to shred, don't worry about someone getting your drive's individual particles and re-assembling them. That level of technology will never exist.