you know, not only was the rapture prediction false prophecy by its definition, giving lip service to having a party or going looting before the prediction time passed shows that some persons' "non-belief" isn't as strong as they'd believe, as those people know that if they WERE left behind, it would be near-certain that they'd be screwed come judgement day, so why not go out with a bang.
On the other hand, joking about it after the fact is perfectly safe.
That said, I wouldn't mind seeing a certain sect in KS "raptured" away, even if the "angels" doing it were just taking them to some place they'd never be heard from again.