Roger has a bunch of old hard drives and wants to know how to wipe them so his data doesn't get compromised. Leo says that you can take the hard drives apart and hit them with a hammer, that pretty much solves the problem, but it can be a bit dangerous and platters are sometimes made of glass and can shatter. You can use a secure eraser like Derik's Boot and Nuke (DBAN). It will write over and erase the data up to 7 times. That usually makes sure the data is unrecoverable. A giant magnet will also work, like SUPER STRONG. A good eWaste recycler should have one.