Rain man is eminems why of saying that everybodys pointing a finger at him and filing lawsuits against him for his so called "controversial lyricism". He is taking a stab at the media for portraying him as an individual who advocates sexual sadism, perversion, mysogony and homosexuality. He also uses rain man as a form of sarcasm in response to being portrayed as the devil. He goes on to say that many kids already use very derogatory ways to describe people that may be homosexual.
Some bars in this song are not so clear but the general idea in my opinion is that Em is taking a bit of a shit on the media.