Unsupervised children...

I work in a smaller music store/piano gallery, so there are lots of things on the floor within reach of small hands. Today 2 boys in the 8-10 year range wander in and start looking around, ok fine. A family comes in right after and I figure the boys are probably with them and ran in before everyone else. As the exchange goes on it becomes clear that the boys are not with them, as the other kids are staying with mom at the counter while they continue to bang on pianos and guitars(thankfully they haven't made it to the drum sets at this point). Family leaves, boys are still here making noise. I ask where their parents are and lo and behold mommy is next door gettin' her hurr did. I tell these kids they need to go back to the salon with her.

Couple minutes later I'm with another customer and my coworker is on the phone because the lady called from the hair salon to complain that we kicked her kids out and said they were Christmas shopping but now they were going to shop elsewhere. Coworker calmly explained that we couldn't have unattended kids here, but she was still mad. Anyone could walk out with these kids leaving us with a lot of legal issues, they could break anything and we wouldn't know who was responsible, they could have wandered in from anywhere, and they were being loud enough to disturb other customers. Thankfully our manager said we did the right thing asking them to leave, but it was still irritating.

Where do you draw the line with poorly behaved kids?