Well, there are at least three obvious candidates:
1. Muslims.
2. Occupiers.
3. A flash mob, which in recently reported cases have consisted of black youts.
If, as the authorities suggest, there are a LOT of people involved, then it’s probably 2 or 3.
Unfortunately, it would be politically incorrect to say that any of these groups are involved, so we may never know for sure.
They will be found—people can’t keep their moths shut about their deeds—they will boast—I bet its part of OWS but it could be any number of things. The truth will come out in time.
I have no idea who it might be, but revenge as a motive keeps coming to mind.....
You forgot zombies.