[sjm_888]

If the theatre is preventing people from protecting themselves, then it is the obligation of the theatre to assume the responsibility of protecting its patrons.

I like your logic.

Me too. Asking your statement as a question If the theater is preventing people from protecting themselves, then IS IT the obligation of the theater to assume the responsibility of protecting its patrons? If the answer to that question is found in the court of law to be Yes, that may be what takes down all the "No weapons in here" signs.

That could be the deal breaker right there.

[Jonty30]

I believe that the courts have ruled that it is your obligation to ensure the guests well being when they are in your house, e.g. drinking.

A private business would be as responsible for the customers within their premises.