Kind of like currency forgers. Anyone can go to the wrong side if that is their personality.
I would put it more that there is not enough money in it to be worth while, forge something that has big bucks like a Luger or some such.
I know one guy who bought Lugers and made them matching parts numbers as the parts only had two numbers on the and he bought enough that he could match up the last two part number (01 to 99)
He did not seem to think there was anything wrong with that and to sell them that way. I disagree vehemently. That of course did not stop him.
I saw one guy who worked harder on staying on workmans comp than if he just went back to work. Really wild. All sorts of a mix out there.