When I was there last year some little kid unsupervised started to slam his fists down on the glass on the game next to me. The older lady that works there was instantly on it and asking if it was my kid is an angry and unpleasant tone. (which I understand)
Kids are kids but the parents are responsible for their behavior and if they can't play nice they should be removed but with as much tact as possible. I can totally see the "my child is an angel and can do no wrong" scenario though...