Scam baiting

From Spam Wiki

Scam baiting is the practice of pretending interest in a fraudulent scheme in order to manipulate a scammer. The purpose of scam baiting might be to waste the scammers' time, embarrass him or her, cause them to reveal information which can be passed on to legal authorities in the hope that they will be prosecuted, get them to spend money, or simply to amuse the baiter.