I've said it before (and so did Tracy
) and I'll say it again....if a professor or administrator has ever made negative comments about your Greek affiliation, or singled you out because of it, they are guilty of discrimination and harassment. It goes against every anti-discrimination code in place on campus and is the same as if they had called you a (insert racial/religious/sexual orientation slur here).
Greeks have to stop lying down and taking the crap that is being heaped on us by predjudiced people who think they're morally superior. When we do lie down like that, it makes us look like we are guilty. No one is going to stand up for us unless we stand up for ourselves.
Sigmagirl, I think if I had been in your situation, not only would I have worn letters every single time I was in that class, I would have encouraged the other Greeks in class to do the same.