The reality is with any Hardware you dispose of and certainly all hardware that you lease you need to Wipe and reload it with a Base Install.
Sure it's not going to stop someone recovering the data on the drive but it's going to make it a lot harder and time consuming. Just how long does it take to wipe a Drive before disposing of the machine?
From my experience after appearing as an Expert Witness in a Court Case over this it's money well spent but maybe that's just me.
However the reality is that once you decide to dispose of any computer hardware no matter where it was previously used there are Security Issues that need to be taken into account by Experts in the field. When you start to allow End Users who are department heads to decide what happens to their Old Hardware you'll end up in a situation where they decide to sell them at the highest price possible to return to their General Revenue Budget to spend as they please. As Labor costs are so high they will run FDisc on the drive and then wonder how their Data gets loose in the wild.
One Government Department here went one step further they didn't even run FDISC on a machine because it didn't come from any form of Secure Environment it was a General Purpose System used in an office with no sensitive data at all on it or anywhere near it.
They didn't even clear the Address Book which had the State Premiers read that as State Governors for our US readers E Mail Address in it and when he started getting emails with demands for funds he got slightly more than a bit peeved off.
You need to treat everything as from the Most Secure Environment possible and treat them accordingly. This costs money but a lot less than what the consequences are when you loose important data.
Col
