I can't believe I'm about to say this, but Timothy makes an excellent point about who we . Here's what Mr. Chambers originally said:
"Robin Hood Airport is closed. You've got a week... otherwise I'm blowing the airport sky high!"
Here's what Mr. Compton said:
"Can someone please stone Yasmin Alibhai-Brown to death? I shan't tell Amnesty if you don't. It would be a blessing, really."
Neither one has the ring of a joke, neither one is in good taste, but the former is defended while the latter is fodder for criticism. Now, back to your comment:
The judge's ruling was based on the idea that an "ordinary person" would not recognize the joke, take it seriously, and be terrified. The point of this campaign is to demonstrate that that's nonsense.
If a complete stranger (and Paul Chambers is a complete stranger for 99.999% of the world) posted the bomb threat on Twitter and you were inside the airport you would probably want to know whether it's a real threat. It doesn't matter what the medium is: Twitter could simply be part of a new MO for a modern brand of terrorist.
In summary:
- No indication of a joke
- Posted on what amounts to a popular public forum
- Threatens death for potentially hundreds of people
That's not even considering the possibility that Paul really was setting up a secret plot to bomb the airport and the evidence simply hasn't been discovered and his friends simply didn't know. That would be rather embarrassing for these kinds of "I'm Spartacus" campaigns..