Most Americans have no idea of the culture of the mosque in America. I've been to pretty much every type of Sunni masjid, from the typical big Islamic Centers that have people from all over the world to the local storefront hood masjid that's like 50/50 blacks and pakistanis, to predominately Somali mosques, and multi-cultural Salafi mosques, ect. And none of them…I mean none of them are on that Khariji/Takfiri/Extremist tip. The hardcore Salafi mosques are probably the harshest critics of terrorism, even offering full on scholarly conferences denouncing AQ/ISIS and the like…complete with proofs from the Qur'an and Sunnah.
We have groups from high schools and college religion classes, even local churches visit the mosque all the time. They are treated like guests, and they come to see for themselves. Anyone that comes in peace to see what it's all about are treated with respect and welcomed. This is the norm, not the exception. Islam is not some secret society with some shadowy figure at the top. The truth is for all who are willing to listen and educate themselves. If some idiot came in trying to talk some pro-terrorist bs they would be asked to leave and have the FBI called on them. There have been cases of FBI agents going into mosques to "recruit" people, only to have themselves reported to the FBI. Practicing, knowledgable, sincere Muslims aren't gonna be duped by these extremist bozos.
The people that carry out these attacks or fly over to join ISIS are usually losers with all kinds of personal problems that get sucked into the online propaganda. They aren't getting this stuff from the true Muslim scholars or the mosque. When I hear morons like Trump talk about closing down mosques, I'm like "Just come visit us and see for yourself. We got nothing to hide over here." We'd even let that scumbag in as long as he came in peace and was respectful.
I get irked when I hear people say that ISIS has an extreme interpretation of Islam. Their ideology doesn't even warrant being called an "interpretation", because that word denotes some kind of scholarly rigor. They have none and they have no learned Muslim scholars amongst them. They are literally throwing things to the wall to see what sticks. As far as I can tell, they don't care about following traditional Islamic codes of ethics or rules of engagement. They just think killing = jihad, and seem to be going for the greatest shock value. I won't be surprised if I hear that they start practicing cannibalism, cuz that's the direction they seem to be going.