Commentary: Refers to the general evil in the world, not a specific kind. A mass noun.
Las Vegas is a wretched hive of vice and villainy.
He's a man weighed down with vice and greed.
WordNet 2.0 Sense Numbers: 1
Commentary: A type of human weakness, or one person's. Can have indeterminatives. A count noun.
Gambling has always been my vice.
He's a man of many vices, but womanizing worst among them.
WordNet 2.0 Sense Numbers: 2
Commentary: The part of a police force dedicated to regulating a specific type of crime, such as prostitution. Usually capitalized. The television show 'Miami Vice' referred to this sense.
John worked on Vice for thirty years.
We sent our Vice Squad to investigate.
WordNet 2.0 Sense Numbers: -