"Black people are disgusting." <-- BAD. I will yell at you.
"I think black people are disgusting." <-- I'll disagree, but that's your opinion.
("black people" picked because I wanted something that everyone would understand and, hopefully, see my position on. If you can't accept a little example, too bad.)
I will also refer to this entry.
Be prepared for me to come out of nowhere, since I don't believe that any of such things that I've heard have been intentional, which means that you won't be thinking that you're saying bad things.
Also note that if you say the second one, that I disagree with you on, you might want to rethink things unless you've got serious evidence on your side. Generalizations usually have exceptions.
(Guess what? Not all prejudices are racial or sexual! In fact, some prejudices might even be things that YOU BELIEVE! How weird is *that*?)