The Mob have honor
What separates wall street loansharks from mob loansharks is the same thing that separates the pigs from any other street gang: an undeserved "legality" that makes is easy to commit crime without any risk to themselves. The pigs murder innocent people with impunity (e.g. Jesus Huerta), and wall street thieves steal with impunity.
Oh come on, this kind of question is just insulting....At least with the mob you know where you stand! hehehe.
To answer your question... The LAW. Its what separates any business or other enterprise.
Um um um...yeah I got nothing :-/
The mob dresses better.
The Mob had a code.