With extortion (the old fashioned baseball bat variety) if you look at recent mafia cases it seems like its mostly linked to loan sharking with some incidences of random businesses or people getting shaken down. The gambino bust involving the sex trafficking in 2010 had a few shake downs and some severe assaults on people. Chinatown gangs on the other hand are shaking evryone and their cousins down from businesses legal or otherwise to just flat out kidnapping and holding people for ransom. Latino gangs are known for shaking down local businesses and vendors in their area. Theres probably alot of lcn gang members that still engage in violent shakedowns when opportunity affords but i don't think theres an actual racket in an area where theres like a weekly collection or something. Im only talking about the actual verbal and physical act where someones walking up to someone and demanding money off of them.