About the only confrontations we have had is with the loose dogs. Our 15# one is always on a leash with harness so I can lift her off the ground when the loose ones come at us. They may be just playing but I don't take the chance.
When the offenders come to get their pet they usually say it is 'friendly', 'just got loose' or other comments. I then tell them I wasn't sure but had my foot ready to keep space between us. This usually has encouraged them to keep their tied up for the remainder of the time. If it is not kept up then I use the ranger for help.