Machiavelli and the Mob

As Machiavelli talks about the relationship between a 'prince' and his state, it's easy to wonder how relevant his instructions are in a time of representative democracy.  After all, if a modern leader becomes too unlikeable, a replacement is found.  Probably the same deal if they become feared.  A modern ruler must have some level of popularity.  Not so for a prince who can rule at least in part with an iron fist. 
But there are some modern day institutions that more closely fit the states that Machiavelli wrote of.  Steve pointed out that as modern corporations take each other over, they have to worry about some of the same complications that occur in 'The Prince'.  The one that came to me was a bit more sinister: the mob.  Consider this passage:

Upon this, one has to remark that men ought either to be well treated or crushed, because they can avenge themselves of lighter injuries, of more serious ones they cannot; therefore the injury that is done to a man ought to be of such a kind that one does not stand in fear of revenge.

If you read that in a Godfather novel or heard it in a gangster movie, it wouldn't stand out.  He also mentions rubbing out the whole family of the deposed ruler, to elminate challenges.  (This rule doesn't really transfer well to corporations!)
Now, I'm not suggesting that Machiavelli ever intended his instructions to be used for crime.  His manner seems to suggest that the actions of a prince were above the moral questions that mere subjects must deal with.  And I'm not sure that this kind of reasoning wasn't already well practiced either.  Machiavelli was shrewd and observant.  He relied a great deal on history to tell him what worked and what didn't. 
I can't help but wonder though, how much influence did he really have on the mafia?