Bin Laden had many rationals for starting the war, but I don't really remember revenge being one of them. Revenge, however, is often attributed to Bush and America since Sept 11 and because Saddam attempted to kill Bush's father.

The message is clear, but with subtle deniability. They are on the other side.

I think they should leave their sign just as it is, but someone could and should rent a sign or billboard in that vicinity which is unmistakably related to theirs. The words on the sign should say something about stopping the jihad. Let it be a shoutfest of citizens speaking freely the opinions they hold. This should be a good test to see if a double standard arises.

I'm sure their sign means to tell us infidels to stop killing the 'soldiers of Allah' so they can install their global Caliphate.
Because, when it comes down to it, if we don't kill Islamic terrorists and jihdists, that is exactly what they will do.
Maybe you should ask the people of the Islamic center if they are opposed to an Islamic caliphate, or sharia law world-wide including America. That's the real question because that is what the jihadists and terrorists are fighting for.

Yes, TS, you are right. I think we should be engaging our fellow citizens of Muslim faith in dialogue. Some of your questions are right on the money. I would rather not see crimes of prejudice erupt around misunderstandings in our country, but I can see that we are definitely heading that way. Unfortunately, should it come to that, many of the Muslims in this country would eschew any personal responsibility for such circumstance and reiterate the hollow mantra that "Islam is a faith of peace". We are approaching that point of undeniability where you are either for America or you are not. For citizens who fall into the latter category their is a crime under which they may be prosecuted: sedition.