They get their news from newspaper and television stories written by liberals, and they listen to their preachers in the mosques.
So how on earth could they have come to believe that the West is attacking the muslim religion? /sarc
Another major source is radical University professors. Just one example: Ward Churchill and his "little Eichmann's" comment.
There are hundreds of colleges and universities in the US that amount to little better than Madrassas when it comes to instilling hate for America, American values and democracy.