PETA put up a billboard in Florida that says "Save the Whales, Lose the Blubber: Go Vegetarian". On it, is an overweight woman standing on a beach. Feministing has a pretty angry post, with a lot of angry comments as well. I think they are right to be angry.
The billboard (which you can see on the linked page) is pretty clearly aimed exclusively at women, and plays into their worst fears about body image. If they want to play up the health aspects or weight loss aspects of vegetarianism, that's fine. But, when they start throwing around words like "whale" and "blubber", they're guaranteed to lose their potential audience on that one. And rightly so.