One that reiterates the request until the patron finishes their conversation, but takes no action.
One that kicks a patron out for breaking the rule, with 0 warnings.
It's the second one, right? Because they enforce their boundaries. It's the same way with people... I respect people more when they say they're going to do something, and then they really do it. That's someone who is trustworthy and reliable. You may not agree with their decisions, but at least you know they have integrity. What kind of boss would you prefer to have? One that will stick to their guns about what they say, or one that won't? The one that sticks to their guns can be counted on to stick up for you when their boss tries to pull on over on your team. What kind of person's word would you take more seriously? What kind of person's words carry more weight and importance? It's someone who is willing to stand up for themselves and tell people "no" if needed.
This is the bit that's never made sense to me. It has not been my experience that I respect people who stick to their guns more than I respect those who are flexible and willing to listen - quite the opposite.
To put it differently, if someone is talking on their cell phone in the theatre and you ask them to stop, are you going to respect them more if they keep chatting through the rest of the film?