I am fortunate to be able to 'zone out' and concentrate on the film, so nothing usually distracts me.
If someone is talking loudly and persistently near me, i will politely ask them to stop, but that's usually a rare event.
Two years ago, at a live concert by Liza Minelli, a lady next to my wife was constantly texting on an i-Pad, which cast a green glow for several feet. My wife politely asked her to stop, and when the lady ignored her, my wife fetched a theatre usher who also asked the lady to desist.
At that point, the lady made a loud fuss, and advised us that she was leaving the theatre, inferring that this was some sort of 'punishment' for us - to be deprived of her company (and the glow of her i-Pad!).
We were in press seats, and usually the press are allocated the same section in a venue, so the chances are this lady was attending the concert for free - as we were, but that did not entitle her to behave in a boorish distracting manner.