Scrub free disk blocks

[Alan Cox]

> In any case, if someone wants your data that bad, it is time to dig out 
> the old sledgehammer and physically destroy the disk.  Otherwise, scrub 
> and other secure erasure programs should be sufficient.

Programs that just write over the data a few times may or may not help
but you never know. A sledgehammer won't help you either if the person
who wants the data has resources.

Modern drives support a secure erase/wipe feature (see hdparm). It's
probably the best option you get short of doing what probably would have
been smartest - encrypting it at install time ;)

There is a school of security thought that beyond the point where it's
cheaper to send a guy round to see you carrying instruments of persuasion
the extra investment isn't actually useful...

Alan