Agreed.

The same applies when you are selling one.

I got two N900s from eBay. One was wiped through the on-board UI. The seller must have thought that was it, device clean. But, thanks to Nokia's infinite wisdom, the wipe did not touch the sent emails which were all left on the device. Genius!

The other device was sold to me as "not working". It just had a dead battery. I found the owner's details on the device which did not match the seller's. A red light went on in my head and I contacted the owner. Luckily it was all legit, the owner sold it to a pawn shop who then sold it on eBay.