It's not the "joke" I have a problem with. If you read my comment you'll see that it's because he posted it publicly. If this was a private message, then I'd have complete sympathy for the guy.
Which was the point I also made. However I'm not trying to argue that it the teenager is entirely in the right. Sometimes several people can all be in the wrong. However right or wrong, he doesn't deserve locking up over it.