I repeat, how in the name of hell are we going to determine which are which if we don't look at them all with a gimlet eye?
The Justice Dept. is consistantly rooting out terrorists and their supporters who had previously been considered moderate Muslims loyal to the U.S.
Al Qaeda held classes instructing their operatives how to blend into their host countries' societies without attracting attention.
Again, we don't and can't unless we do exactly what you apparently describe. It is patently and obviously unfair. If you disagree, fine.