And for the record, I'm not against someone briefly responding to a text. It's when someone does so for over a minute that I start to get pissed off. If someone is a doctor, vet, a parent or whatever, they can quickly see what the message is about, reply, and then either continue watching the movie, leave, or finish the conversation out in the hallway. Not a big deal as long as people are considerate.
Perfectly reasonable, but not possible if someone is illegally distrupting celluar communications.