We tend to pick commercial site for their remoteness, the ones we mainly use are in Lincolnshire and they are a minimum of 2 miles from anything so never had any site problems, and if there is the sites we go on sort it there and then. One kicked a drunken family off last year for being too loud, like the owners told us kids play loud is ok as kids need to play, but adults shouting at ach other when they are sitting at the side of each other isn't on.
As for security I never worry about it, as a always on guard dog owned by a 6'6" large built bloke tend to put people off lol