Has anyone who owns a large/giant breed dog....?

experienced discrimination because of the dogs size alone? Or because of a mix up in breeds? I own two very large Bull Mastiffs. For those who don't know about the breed, they were originally bred in England, a cross of a Bull Dog and English Mastiff, to help the Game Warden keep poachers off of crown land. They are excellent guard dogs, pin down an intruder rather than bite, and are dubbed the gentle giant due to their loyalty to family, children and other pets when socialized early. I have had many run ins, with neighbours, as well as strangers, who have felt it necessary to call police, as the thought myy dog was a "pitt bull" or were just scared in general due to their size. Afew weeks back we had our dogs for a walk along the parkway, fully collared and leashed, when a lady walked past with a lab, who barked at us, thus making my dogs bark back. She then turned to her companion and said something to the effect of our dogs should not be allowed out in public! Her dog barked first and was pulling at its leash! we have even had people with small breed dogs, scoop them up and jump off the sidewalk as if our dogs were about to snack on them. Does this happen to anyone else?