Aftermath of Bruce Sterling's open-door SXSW party

As is traditional, Bruce Sterling finished out this year's SXSW interactive festival by throwing an open-door party, with 600 in attendance. He's posted photos of the (surprisingly tidy) aftermath.
The cops showed up. There was no dancing or loud music. Those were human beings *TALKING SO LOUDLY*that they could be heard as a steady dull roar two blocks away. We've had SXSW parties here, every year, but we never set off the cop-ometer before.I had to hustle all the guests inside and shut the doors, whereupon the party immediately became MUCH LOUDER.