Possibly boring repetition here, but after 9/11 I traveled across the country several times and always chatted with my Muslim cab drivers. I was open with them about my religion (Judaism) and we discussed religion and many other things. All conversations were friendly, and many times they were fairly deep. At some point in each, I gently asked, “But there are guys at your mosque who agree with or support bin Laden/al Qaeda, right?”
The answer, 100%, was always yes. Always. Usually the cabbie would immediately say, “But I don’t hang out with those guys / I have nothing to do with them.”
There are probably people at EVERY mosque in the land who agree with ISIS or Al Qaeda.
My last cab (Uber) driver, just a couple months ago, was an Afghani. He told me that Al Qaeda looks down on ISIS as not being true Islam and being just out for gore and violence.
At least a couple million in our country alone.
From 2011: Pew Report: 1/3 of US Muslims Support Al Qaeda, Suicide Bombs; 25% Came to US Under Bush, Obama