The demonstration is much like those of the Sunnis in Iraq that we see from time to time. Those men have benefitted from money, status and jobs handed out by the Palestinean Authority because they are Fatah members and Fatah controlled the PA. Now they are facing a loss of all three and they are angry. Given that Palestinean politics often resembles rivalries between street gangs more than it does western politics, the violent demonstration is not surprising. They are looking for a scapegoat and they will be a source of trouble for Hamas because they are armed and discontented.