True story - Today I was pulled over by a patrol car while I was bicycling at about 5:45 pm. The policeman told me that the police dispatcher had received report that someone had called in to complain about a bicyclist singing loudly while passing a nearby local high school. After assuring the policeman that I wasn't the singing culprit, he apologized and wished me a good night and we went on our ways with no hard feelings.
No doubt the informer felt real proud of himself for being such a moral citizen reporting on a potential evil law breaking bicyclist.