About 18 months ago a friend of mine invited me to an underground boxing match in Copenhagen. When we got there I was introduced to the guys that were going to fight each other that evening - two russian guys that were best friends. These guys were fucking insane, one of them ended up with a broken arm and the other one had a broken nose, two broken eyebrows and was bleeding A LOT. I guess friends do that to each other
After the match, they were driven to the emergency room and were patched up and then they came back to the afterparty. During the evening, they ended up telling me a bit about themselves. They had come to Denmark 7-8 years ago with their parents, who are high paid scientists, but they had become bored because they had no other friends and had turned to crime.
Besides boxing, these guys are some of the biggest arms dealers in Copenhagen and the weapons come from their contacts in Russia.
I'm not sure that I would classify them as mafia, but they are some of the last guys I would ever fuck with.