I had posted this in Microsoft security discussions So I thought That you would be able to get some good information from it too

I rember a few months back two MIT students who bought $1,000 worth of old hard drives and uncovered a wealth of corporate and personal information some of the harddrives were from atm machines, people's old computers Etc here is a link that Simson Garfinkel wrote about it. http://www.computer.org/security/garfinkel.pdf