I think everyone who is a vegetarian has experienced some harassment. Mostly I have just gotten snickers or rude comments. Often people are clueless about what vegetarianism is and ask a lot of questions placing me in the position of explaining vegetarianism. I end up being a de facto representative for all people who don't eat meat; that's exhausting when all I want to do is chow down. Even my own family has been intolerant at times and ridiculed me. The worst thing was having meat put into my food "as a joke." Yeah, I was laughing after that.
Here's an article about a man who was fired from his job because he was vegetarian. His boss thought he was gay. The discrimination just keeps coming.