There is an urban legend about a kid saying "Cram It, Clown!" to Bozo the Clown on TV. The 'official' accounts have been largely debunked as documented by this snopes.com entry. Well, I found out from my lovely mate where the story may have originated from. This is something she witnessed herself. Her daughter was watching a local live version of Bozo the Clown. The children were picked at random from the crowd to participate in a guinea pig race. The race began and the guinea pigs had varying degrees of success as they moved to the opposite finish line. One child became frustrated and said, "run you little bastard", at this steed. Bozo turned to the child and sincerely said, "That's a Bozo no-no", with his finger wagging at the kid. Hands on hips, the child retorted "f*ck you clown". My wife reports that the camera man immediately dropped the camera. When he recovered, the audience viewed the shocked and stupified face of the Bozo actor while sounds of butt spanking and a child's cries were heard off camera. The station then switched to a commercial. My wife had to walk into the kitchen to recover her composure and then she told her daughter that the words heard were not appropriate. She reported the next day that her co-workers told each other "that's a bozo no-no" whenever somebody swore.
One of things I love about my mate is her breadth of experience and keen memory of details. I very much believe her when she relates a tale like this.
My wife reports that the event occurred in the early 70s and viewed in Charleston SC during an early afternoon children's programming block. Bozo came on after Romper Room. The studio set was small, only six high seats in the bleachers and about ten feet long. I could not find a possible match on the wikipedia site.