Martin Lee knew all the reasons you shouldn’t respond to spam e-mails. As a software engineer who studies how to block such messages, he’d warned against answering them himself.

But he couldn’t resist. Lee was struggling to figure out how to stop an especially persistent form of spam - the type that informs recipients they’ve won the lottery or are sought for a new job, which can masquerade as legitimate e-mails and evade spam filters. As Lee pored over the messages, he wondered who was sending them and who would be tempted to answer them. And he decided to find out - by engaging the scammers in their own game. He bit into some Nigerian spam - to fight it