"It is quite easy to over an entire disk surface with available proprietary software."
Actually its quite easy to erase an entire disk surface with available FREE software...
Lot of paranoia here and business "cover-your-ass" here. After several cycles of DOD standard erase/overwrite it is theoretically possible (at the cost of great time and expense) to reconstruct small and essentially random scraps of data.
If you're a spy and you are targeting a government or major industrial secrets it may indeed to worth it - intelligence mostly is reconstructed from acquired scraps.
To believe that the average totter finding your anonymous (securely erased) PC on the dump is likely to spend much expertise, time and money in order to try and find (probably not succeeding) your bank PIN number or your collection of smutty pictures stretches paranoia and common sense too much.
The same goes for Joe Bloggs whom you sell your securely erased PC to.
If you are trawling for random data that may be useful for nefarious purposes then for a start, a spot of war-driving will find dozens of open networks with essentially open PCs behind them that are a far more worthwhile and productive target.
And if I think Fred White down the road may have some interesting data on his home/work PC that I'd like to have a look at then I'll just steal it and comb through it at leisure.
Time to finally put this recurring canard to bed.
Mac
