There isn’t one!
The problem is in people being dickheads.
I’ll elaborate on that a bit…
When people take pictures at events where pictures are not allowed; that’s a problem.
When people make calls in quiet spaces; that’s a problem.
When people do anything that they agreed not to do at an event, even without a cellphone; that’s a problem.
None of these are cellphone problems, but all of them are dickhead problems!
Dickhead problems are behavioural problems. Some behavioural problems are due to personality and intellectual problems.
To put that last comment into somewhat more prosaic terms. Some people are entitled, self regarding and stupid enough to think “Yeh, but that doesn’t apply to me right?”.
Yes to you! Especially and particularly to you because you are an entitled, self regarding idiot with no regard for the restrictions that you yourself voluntarily agreed to but also with no regard to the rights and perfectly justified expectations of others in the space.
Those people have every reasonable expectation that everyone else will give equal regard to those rules and restrictions.
People bang on about banning cellphones, confiscating them, deleting media etc.
Ban dickheads instead.