Well first, anything if repeated often becomes unfunny. Second what you described is harassment.
Somewhere on a radio station someone is saying something that angers me. How can I find these people and how can I get them fired?
Who said it has to be funny to be entertaining. There are probably enough perverts who would find the 60-second rape fantasy of your mother extremely entertaining. Should it be protected free speech?
Second what you described is harassment.
And what Opie and Anthony had on wasn't harassment? Harassment is subjective. If everyone finds a rape fantasy of your mother great entertainment, who's to say it's harassment?