Very cool, if true

I think it's a stupid reaction.

If the police read a tweet like that and genuinely aren't sure if the guy is serious or not - and I think it's reasonably obvious he's not, but never mind - then maybe they have cause to investigate. Talk to him, maybe search for explosives. But if they don't find anything, then drop it, believe him that it was a joke.

Actually I can't tell whether they're saying to him "we still think it was a serious threat", or "we know it was a joke and we're punishing you for making such a joke". I'm not sure which is worse.

I agree with most of the comments on the Register.

One of the commenters says he's just re-tweeted the original message. I guess it could go viral and have thousands of people repeating it. That could be interesting.