It's only implied, but the coins also bring a certain required 'illegitimacy' to a transaction. ie, if I turned up with cash to organise a hit... you might won

It's only implied, but the coins also bring a certain required 'illegitimacy' to a transaction. ie, if I turned up with cash to organise a hit... you might wonder who I was and if I was a cop. But if I instead rocked up with mafia gold, well then I've passed the sniff test for being part of the underworld.