PSA: Many criminals enforce 'don't steal from us' in with punishments that are more brutal and with a lower procedural protections than the state does.
Are all buyers of substances the U.S. controls inherently “professional criminals”?
Does the belief that someone is a criminal justify taking their money?
(I trace cryptocurrency professionally, depositing is key to identifying clusters and it sure is nice to get the money back)
“Vigilantism” : well-established net negative for any land of law
Despite what one sees in the movies the general problem one has is not some guys running up with masks on ripping you off of the money you made selling drugs, but rather the people you have fronted drugs to not giving you the money they owe you or the people you are buying drugs from ripping you off (using drugs because it is the most generally distributed type of organized crime but similar situations apply to other forms of organized crime)
The problem then is that you have people who have taken from you, there is no system to force them to pay, you must assume the state's monopoly of violence to get what is owed or decide to write it off. If you write off too great of losses you cannot stay in business, if you write off losses too frequently you cannot stay in business, and in writing off losses you may give other people the idea that they can steal from you as well.
Thus as you get to a certain level of organized crime you have to punish the people who do not fulfill the contracts they have undertaken with you.
This is sometimes also described as the actual origins of the mob, because they were the guys who could enforce contracts among the various criminal factions (by using violence)