The bad news is they have taken over the Mosque that is one of Islam's Holiest Shrines....a good hiding place as the Shiites not in Al Sadr's camp would revolt lest any harm come to the Shrine. No, that's the good news. If they're in the Mosque, there's no reason why we shouldn't let them stay there for months and months, with no electricity or water. Eventually they will come out firing (good), or drown in their own crap (better).
I'd like to see their gaunt faces and protruding ribs after a few months of siege.