The San Francisco Committee of Vigilance was a popular ad hoc organization formed in 1851 and revived in 1856. Their purpose was to rein in rampant crime and government corruption. They were among the most successful organizations in the vigilante tradition of the American Old West.
"We are determined that no thief, burglar, incendiary, or assassin shall escape punishment either by the quibbles of the law, the insecurity of prisons, the carelessness or corruption of the police, or the laxity of those who pretend to administer justice."
San Francisco Vigilance Committee 1851