Get some nudes of him. Do a setup if you have to. Have her put it as her timeline pic and send him a message. Within 3 days he'll stop. If nto send them to his mother and explain the situation. :) This happened to someone I know. They did this and he never pulled that crap again. The only difference was she already had his nudes from when they dated (he's not very smart apparently).

Call the cops of the city that the crime was committed

Just post him in the m4m section of craiglist. Make him change his cell # and emails.

Wouldn't be hard to get his address, just go on a little phishing trip... maybe he just won a new iPod? Where should we ship it :thumbsup