Ignorant (for lack of a better term) hams often assume that their ham license gives them free reign of the airwaves from DC to daylight. They'll often pop up on CB, MURS, FRS, GMRS, commercial and public safety frequencies. They'll give all kinds of amusing justifications for doing it, none of them legal or based in any reality.
Unfortunately, you can give hams a lot of spectrum to play in and very loose requirements, but some will still find a way to mess it up.