Pretty much.
The first minute of this video tackles that common jibe against free speech, although all of it is superb.
http://www.youtube.com/watch?v=jyoOfRog1EM
If somebody shouts 'bomb' in an airport then by all means have security look over them as they would anyway. By all means, if an airport (private) wants to ban certain phrases on it's private property then that fits in with free speech under property rights - but under no circumstances should somebody be arrested for shouting bomb in an airport or fire in a crowded theatre.

