It happened here that I bought a ps3 with a malfunctioned hdd, so I had to buy a new drive. Since I am a cheap bastard I thought second-hand would be great. As soon as I tested the new "120 gb hard drive" I noticed that 40 gb were missing. Checked the whole drive and found horrifying content. Called the police within 5 minutes after seeing the horror - I am happy that they understood the nightmare of this situation and acted understandingly that I was not a culprit, but a victim. Since the seller had his credentials on the delivery box which was in the same town as me, backtracking it wasn't that hard. They confiscated my hard drive and didn't offer anything in exchange, other than promising that the right person will pay for those atrocities - more than enough.
Freaking eastern Europe.