Joe Valachi reported at the Senate hearings that he made ~$150k/year during WWII on stolen and counterfeit ration stamps, but his earnings dropped dramatically after the war.
I think some Mob guys make out. But probably more are like that scene in "Donnie Brasco," where they're reduced to busting open parking meters.
Ntra la porta tua lu sangu � sparsu, E nun me mporta si ce muoru accisu... E s'iddu muoru e vaju mparadisu Si nun ce truovo a ttia, mancu ce trasu.