I suppose you could call that offended as well, although you could also say that you are angry that they caused offense to other people. Or I guess you could be angry that they have influenced everyone's opinion a certain way. It's confusing because being offended doesn't feel different from other types of anger, we just happen to have a word for anger which comes from that particular source.

I guess what I'm getting at is that being offended isn't an emotion at all, it's just one form of anger. The lines concerning what types of anger classify as offended are a bit blurry.