I didn’t say that I must check my phone every time I go to the toilet. Only that being able to check my phone (for example, to check if I have any messages from people I care for at home) is a useful thing.

And I never said that I was worried about terrorism. Only that having ready access to my phone in any emergency situation (again, I pointed out it would be more likely a fire alarm than a terrorists) is helpful.

I don’t think concert venues do anything to enforce any sort of phone etiquette. I dislike that they’ve went for such an inconvenient option when there are softer, policy based alternatives in between doing nothing and locking up phones. Cinemas manage to enforce phone etiquette with much fewer staff per guest. Of course it’s common to see someone light up their row by checking their phone, but if it’s persistent (like the drunken heckler), cinema staff would eject them.