Um............san Francisco? Several years ago Zombie did a photo essay (censored and un-censored versions) of this "event" with commentary. From what I remember the sfpd leo's were told to no interfere with any activities unless someone was "in danger". Totally disgusting display of open "relations" on the public view. Maybe another erf quake is in order.
If you read “Population Density and Social Pathology”, John Calhoun, I think it was Nov, 1970 Sci Am you will find out.
The scarier parts are in the near future - infanticide, cannibalism, even worse than that...