All 'bad behaviours' are acceptable in moderation. Chatting, texting, drumming a bit out of time or whatever. I think it only becomes a real issue when whatever it is genuinely - and consistently - impinges on the enjoyment of other participants.

As for smartphones in particular, I'm not sure why people who feel compelled to continually study their Facebook updates, even bother attending other forms of entertainment at all? At the cinema it's such a drag to have your eyes pulled away from the action by a brightly lit screen sat in front of you. Ugh!