Shows how much you know. I unknowingly buy tainted MP3s from a retailer. Under the doctrine of first sale I can re-sell these MP3s. So now I legally sell a ful

Shows how much you know. I unknowingly buy tainted MP3s from a retailer. Under the doctrine of first sale I can re-sell these MP3s. So now I legally sell a full mp3 player or maybe lose it and someone hands it into the police but I never claim it. The new owner now has a means to do me harm.