I'm probably not going to do that. Responding to a clearly fake threat with violence (via police/government) strikes me as wrong and excessive, especially when it's just some stupid kid.

He hasn't caused much harm as of yet. He didn't steal any bitcoins or release any sensitive info. (The screenshots didn't contain any useful info.) The worst he's done is convince some people to send him a little money. I advise restraint, especially since we don't know for sure whether this guy actually is the hacker. I haven't seen much evidence of that.