Social norms are different in different groups. I have told people that what they wrote could be considered racists and gotten a reply back that they wanted to be clear that they were racists, quite proud of it, and that I was an idiot for not seeing the muslim thread (in a discussion that was not at all related to terror). I have seen the same people belate others for questioning that we should throw all muslims out and arguing that every single muslim was a terrorist ala The Norwegian terrorist.