When I was at VOJO's (a while back) sat with a friend, a couple with 2 border collies came in. There dogs off the lead in the premises, and straight over to our table. One of the dogs wanted something throwing so I bent down to pick up the stone or whatever it was and the dog nipped my hand. The woman owner looked over and I asked if the dog was up to date on it's inoculations, she asked why and I told her that it had just nipped me, she called the dog over, put it on the lead muttered something to the guy with her and that was that!! Good job my son hadn't been there, as he would have probably been the one to get bitten.
With regards to dogs off leads, they shouldn't be. It's bad enough walking down the front with the street dogs around especially when you have a dog like mine that doesn't like being approached by other dogs.