How do you decide if your source is a "pumper"?

I was talking to someone couple days ago about Jim Cramer, he has been going on about John Deere and ethanol. He even throws on a cap from them and had the show with hay stacks.Do you believe he was pumping them so to speak?

Do all magazines,new papers,internet sources,etc…Tend to lean toward certain stocks for the sake of “pumping” companies they own or do they truly believe they are giving information out?