a guy had one go off at the Met and he was quite publicly humiliated. Even written up in the paper.
So I guess taboos are effective checks on social behavior.
But don't tell that to all the leftists whom it benefits.
I LIKE it when they remind you at the beginning of the show to mute or turn off your phones
At my daughters high school play the teacher said one went off during a crucial dramatic scene last performance and if it happend again she was going to run on the house lights and come down and beat them with her baton
everyone turned them off (that I could see)