I see he's just been jailed. I frequently hear stories like this, sadly, and a few years ago I personally found a bomb threat message on a flight from LA (sorry, I can't go into details). There's a lot of stuff like this that goes on that doesn't make the news.

And we're finding that we're being increasingly treated as potential terrorists by governments and aviation authorities simply because (they've noticed!) we have access to the flight deck. The paranoia never stops.