sanjosebaz
The grey area is: what am I to expect if I say to an FA: "The cockpit door is open; if I were a terrorist I could get in there now and hijack the plane"?
This, more or less, is what the guy was arrested for. Now, the words I used may have been more explicit in their meaning - i.e. not threatening. However, none of us really knows exactly what this guy said or how he said it. Was it meant as a joke or not? We don't know, and we may never know. We do know that airport security took it as a threat, which it most certainly wasn't. Sometimes we say things in a light-hearted way with a smile to conceal the fact that we're a bit nervous, not to say scared.
The grey area is also this: how do we decide what is a threat, or a stupid and inapropriate joke, that deserves being disembarked and arrested, and what is a serious comment on a concern for safety. Is it the way we say something? Surely nothing that subjective! Is it the words we use? Does that mean that we can't use certain proscribed words like "gun" and "hijack"?
The point is there IS a grey area, so people would do well to think about things like this before going off the deep end and ranting.