I haven’t seen that many lately (in the past week or so) but a year or so more ago there were a lot more.
So why are they here? Fox News.

(Could be joking…)
Most likely, its because the sort of people who frequent forums tend to want to be very fierce. They can’t do it in reality so they do it online–and they love to hate, and try to justify their hate, and spend time around people who they can hate along with. And those people like telling lies and half-truths to spread the lies (and yeah, Muslims who hate on Christians are the same–immature, childish, and very unsophisticated in their understanding of religion, and fed a bunch of lies by whomever they’re hanging with.)
But Christians here (only because they’re the majority do you notice it maybe) hate on Muslims the way some hate on Catholics or Protestants or Mormons. And Muslims hate on the others the same way. With arrogant immature ignorance. Makes you want to chase them around and step on their fingers, doesn’t it?
Anyway, even here you get Muslims and other non-Catholics proudly hating on Catholics.
The internet turns us all into raving lunatics.