Why the "Evil Lawyer" Jokes?

Alright I've noticed that lawyers take allot of crap. I don't know if this is just a planned joke against lawyers and there is no actual meaning to it, or if people actually think lawyers are bad people. Tom Clancy makes references to lawyers being bad people in some of his books, and I hear two separate lawyer jokes today at school. So, if these jokes are true, why are they so bad? I'm not defending lawyers or anything right now, but I just want to know what people that are bad about lawyers that gives them the liberty to make jokes about them. Sanks