DH and I took a flight recently and a fellow across aisle was watching R rated movies. He had the earpiece in and the closed captioning on (?) and the little girl in front of us who was unaccompanied was watching the movie. The man noticed but didn't seem to care! I was appalled that someone could be so irresponsible in front of a child!
I also disagree - it's should be the parents responsibility to watch the child.
I try not to take mine unless I have work to do, that I couldn't finish in the office. I do lots of presentations to clients. I also write reviews for my staff since flying durring business hours is the only time I get to do this.