Actually in my experience science threads are some of the nastiest threads on the entire internet. Not sure why.
I think it's because of the creation/evolution and religion/science conflicts. I'm sure that people from both sides have been guilty of bad behavior on those threads. Speaking for myself as a creationist, I've certainly encountered some hostility from Darwinist/atheist types, though I'm usually willing to engage in friendly, good-spirited debate.
The single meanest place I ever saw on the net was the web site for Myth Busters. The worst day around here was like an average day there give or take.
People kept asking the same questions.
The two I remember the most was "They should test if they went to the moon" and some variation of "They should test what a real samurai sword could do".
It was rough. People were just so invested in their opinion. Just nobody would admit to any wholes in their theory whatsoever.
Then you get the whole jeopardy "I know everything about science" crowd that would attack the laypeople.
It was just horrid. I stopped watching that show after that. And I just noticed the other day they did a moon landing episode