Were Muslims involved in the mass killings in Paris and San Bernardino?

Yes. As usual. Most ideological attacks these days are perpetrated by Muslims.

You know they were. The question is why young men and women become radicalized and commit these attrocities. Demonizing Muslims and stirring up islamophobia as Donald Trump does certainly doesn't help.

Yes, and ISIS has killed more muslims than any other religion. (I heard this on the news). Don't assume they don't kill their own religion, they do because their way of following the religion is different than how the good people follow it.

Americans killing Americans in San Whatever

Yes , user Biiff nailed the real question to be asked and explored.

If musical taste is subjective, does that apply to Nickelback fans?

Yep.

Uh, where have you been? Yes, they were muslims.

of course

Do you live in a cave?