I came across the following site today and found it rather amusing. Partly for the product and partly because the National Pork Board probably spent a hefty sum in having the letter drawn up.
ThinkGeek for April Fool's Day posted what I hope is an obviously fictional product to it's web site-- Canned Unicorn Meat. The National Pork Board is concerned that it is a little too close to it's "the other white meat" slogan and has a 12-page cease and desist letter sent to them. The second mistake after paying to have such a letter drafted is in sending such a letter to a site that is going to further ridicule it. And sadly, what the National Pork Board and their lawyers missed, but the ThinkGeek people got right is that they are in fact covered because a) it's not really close to their slogan and b) it's covered by parody. Which, really, makes it all the more humorous.