tangor - 2:35 pm on May 10, 2009 (gmt 0)

@kaled ... you'd be absolutely flabbergasted as to what can be recovered from overwritten data, or how deeply the magnetic substrate goes, or the sensitivity of detection and recovery software these days.... and I'm not talking about the high-end spook stuff used at police or government labs.

Nothing substitutes the human brain. We see things that computer programs can't... that's why captcha's work (even if we don't like the way they work). If we get 7bits of every byte we got it all. More or less.