From another thread:

Quote Originally Posted by autobreadticon
The majority of stabbings these days occur from drunking Caucasian after a night of drinking, and the majority of them take up kick boxing classes.
Pppftt, amateurs. The good knife fighter is the one who casually strolls past you then suddenly turns and stabs you in the back multiple times. You can learn more about realistic knife defence by watching this video - the guy there is an accomplished practitioner of several styles of martial arts (including Yin Baguazhang, Xingyi, Taijiquan etc.) and also grew up in rough predominantly black ghettoes in the U.S. His home page is here.

I don't know why, but in my experience the majority of people I've come across who train in Thai kickboxing are thugs. I've only met three practitioners of Thai kickboxing who aren't thugs - one of whom only did it for a year before he quit, and another who actually practises Muay Boran, which is the original traditional Thai martial art which Muay Thai evolved from. Muay Thai is the sport whereas Muay Boran is the martial art - their form is far more like other traditional martial arts and quite different from MT/Thai Kickboxing. I'm not saying that all practitioners of MT/kickboxing are thugs - this is just from my own personal experience.