The American justice system, by the numbers:
1.7 million criminals behind bars.
4.3 million people on probation.
700,000 people on parole.
From Wilson Quarterly, Summer 2010, page 74, citing, American Interest, March/April 2010.
Bonus: "California's prison guards have become the state's largest personnel expense, creating a situation in which the government's cost to house each prisoner is an astounding $45,000 per year." More HERE and HERE.