I know PETA is famous for protesting other products and events, but has anyone ever protested PETA events? I'm not sure if it's ever been done or not...I'm sure it has somewhere.
Probably not directly. Most people have better things to do than to waste precious calories dropping to PETA's level. That, or the protest consists of the crowd driving them away.
At one particular school, PETA tried to protest the school's serving of milk with the children's lunches. They brought in some clown dressed up as a cow, and the kids simply hurled milk cartons at him.
Edit: Found the story:
http://www.plastic.com/article.html;sid=02/10/17/17005657