I encountered a fully grown Great Dane(and its owner) at Lowes last year. I don't care how tame it appeared to be, or what store policy is, the dog didn't belong in the store. Clearly not a service dog.
My other experience goes back 15-20 years. On a plane, I watched the flight attendants fawning over a dog(including petting it), and then go about there business without ever washing there hands. Found out later in the flight, it was a dog from some sitcom. ****ed me off to no end. I remember complaining to the airline, but don't recall what compensation, if any, that they gave me.