The World’s Biggest Crime Organizations: Yamaguchi-gumi
The largest criminal organization in Japan and one of the biggest crime organizations in the world, the Yamaguchi-gumi boasts over 55,000 active members. It was founded before World War II and can be traced back to the labor union of dockworkers.
http://www.youtube.com/watch?v=OB17kKq40C0
The organization amasses billions of dollars a year through various criminal activity including extortion, drug dealing, real estate, arms dealing, gambling, Internet porn and stock market manipulation. One of the members even assassinated the mayor of Nagasaki because he damaged his car in 2007.