If these dufuses would just renounce the violence and hate (some would say that's renouncing part of their religion), we wouldn't need monitoring. And monitoring peaceful muslims could be a foot in the door to government monitoring all of us.
You raise a very good point...it is definitely a delicate matter.
Ya know, I would accept a few "informers" inside the mosques, and I would accept the synagoges too if people feel a sincere need to be fair and balanced. What I don't like is our foolish willingness to let whatever goes on in a house of G-d to be off limits. At least in Iraq our guys have quit this side steppping. (How many arms have they found stored in the Mosques?) Quit worrying about monitoring, if they say they are being good, will you believe them? Have they not ever lied to you?
Now, if time passes and things are very cool, maybe then monitoring does not make so much sense, but this will be a long time from now.