http://www.markarkleiman.com/archives/crime_control_/2004/07/what_i_learned_at_the_executive_sesssion_on_gang_violence.php

This blogpost on gangs doesnt seem to realize that one of the reasons why gangs exist in poor african american and latino communities is to function as discipline and  judicial forces in places where the cops and lawyers are deeply ineffective, mostly b/c they are aa or latino.

Not defending mass violent behaviour, but it does exist for a reason.
(the rest of the post is actually pretty good reportage from the front beurcratic (sp) lines