Seems us advertising types aren't the only ones who get a little sensitive when material gets ripped off. The nicking of jokes without proper credit is an even bigger sin apparently.
If you've not caught wind of Cheggers-gate, here's a very eloquent and entertaining perspective from Ed Byrne about the whole thing. You can read it here
If you can't be arsed, it's at least worth watching Stewart Lee hammer Joe Pasquale on the same subject. This was also featured on Ed's blog piece. Thanks, Ed. Credit where credit's due and all that.