Regulators

Fallout
Lead by the sadistic Caleb, the Regulators are a vicious gang that serves as the "police force" of Adytum in Southern California. Nominally under the authority of Adytum's mayor, Jon Zimmerman, they in fact manipulate Zimmerman and control Adytum's affairs, ruling harshly, expropriating a good part of Adytum's industrial wealth for themselves, and enforcing forced labor on Adytum's citizens. To legitimate their authority, they have claimed that the Blades, a survivalist group to the north, are a threat, and frame them for crimes such as the murder of Jon Zimmerman's son.

Fallout 3
In the Capital Wasteland, the Regulators are a group of vigilantes, who wear cowboy style hats and dusters and operate out of a farmhouse. If the player has the Lawbringer perk, he/she can trade fingers taken from the corpses of evil humans killed by the player, for good karma and Bottlecaps. The Regulators will also attempt to claim the bounty on the player's head if he or she commits serious crimes.

Appearances in games
The Regulators appear in the original Fallout and in Fallout 3.