When my father was alive, he served as an usher for a big name megachurch. Dad was a big (not fat) guy and he would help some troublemaking visitors
“find the exit”. I used to joke that he was a bouncer. I suggest that all churches have a plan and some special ushers on call in case a troublemaker shows up. One of these ushers needs to have a video camera to record everything that happens in case of the inevitable lawsuit.
Your father was upholding freedom of religion, IMO.
Sooner or later angered Muslims in this country are going to get the notion they can invade & trash churches, just like they do in Egypt. A sermon critical of Islam, a spy in the pew, and here come the muzzies.
I believe churches should appoint quick response teams consisting of the men of their congregations, to deal with Islamic demonstrators. They’ll show up with placards, the media, & ominous demands for apologies. It’s coming.