What if it had been named "Teddy Ruxpin is my friend", but the pilot doesn't know whether that's a secret code for "I'm going to release aerosol sarin nerve gas on the plane"?
Should he react to all messages as if they are threats, because no matter how small the risk is, more than zero is too much?
If you can't know whether something is a threat or not, the only reasonable response is to treat it as a non-threat. Anything else leads to absurd outcomes that make it harder to protect from real threats.
>The right to free speech does not mean the right to ignore the predictable effects What are the predictable effects for the scenario in question? Please enlighten us, because most of us are apparently unable to predict those ourselves.