Ever been tempted to complain about howling children in a pub or restaurant? Perhaps best not to bother, as you run the risk of getting a bottle smashed over your head. And in future, give your business to establishments that have an adults-only policy, or at least have a completely separate room for families. Realistically, if you do feel the need to complain, it may be more prudent to do so to the management rather than directly to the offending customers.