Almost as funny as walking into a bank with a motorcycle helmet on and shouting, "I bet you'd be worried if I had a GUN!!!" What a farkwit, deserves whatever he gets. Fully support the airline taking it perfectly seriously. Now for flippancy.
I know lots of people have been hammered for just the same stupid "joke", but I still have to bite back the urge to say something witty about bombs when boarding an aircraft. I suspect this dates back to our caveman ancestors who would wave a heavy stick threateningly within view of the family mastodon before boarding for the morning commute.
It might help the well being of people about to locked in an aluminium box and fired in the sky if the cabin crew looked a little less supremely confident when prospective passengers are quaking. Not to actually look frightened, just a little less smug