That creepy laughter. Sends a shiver down my backbone.
It was hysterical laughter. The "humor" of the mob.
Get used to it. This is the pattern that we will be seeing as things come apart.
The pattern will be that flash mobs will loot stores and disappear. Then they will be back later and loot another store. The process continues until stores go out of business, in a ring going further and further out from the "inner city" core.
There will not be zombie hordes hitting residential areas because they know that homeowners can and will use deadly force to protect their homes, but the flash mobs won't face fire if they loot a WalMart or supermarket.