Regulator (Fallout 3)

The Regulators are a group of vigilantes who wear cowboy style hats and Regulator Dusters after the fashion of gunslingers. In the Capital Wasteland they are led by Sonora Cruz and operate out of a farmhouse. Unlike the corrupt Regulators seen in the original Fallout, the unrelated Regulators of the Capital Wasteland are truly just-minded and seek to punish evil.

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, such as destroying Megaton or enslaving people in the Capital Wasteland.

Members
Regulators wear Regulator Dusters, and use laser weapons (Laser Pistols and Laser Rifles) although more commonly they are equipped with Combat Shotguns, Chinese Assault Rifles and Combat Knives. In terms of durability and combat challenge, they are about equal to a Talon Company Merc (although with severely less protective armor). Regulator patrols typically operate in 3-man squads when searching the Wasteland for the player character if that player is evil or very evil. They are no more deadly or effective than their evil counterparts Talon Company Mercs and it would be wise to take out the one with the longest range weapon first and then backpedal (whilst firing) to some cover and take potshots at the one with the Combat Knife or Combat Shotgun.

If you have the Lawbringer perk, a Dead Regulator will be found outside of the entrance to Arlington/Wasteland Metro in Arlington Cemetery North. He will have a bounty note for Junders Plunkett. It says he was last seen in Canterbury Commons, but really he is in the nearby Arlington House. You can kill him and take his finger. It is worth 1,000 caps back at the Regulator HQ.

Lucas Simms, the sheriff of Megaton, is also a Regulator But is not IN the Regulator faction (Retired?).

Bugs
A bug sometime occurs, dubbed the "racist bug", where a regulator may have white skin color on his face, but when the coat is removed, the skin turns black while the face stays white. This also happens on Talon Company Mercs (confirmed all platforms).
 * There is a bug where a player can pick-pocket a regulator, and he/she will have a named bounty for the player on them, even if the player is completely good. (confirmed all platforms)
 * Sometimes the Regulators will go through their dialogue as if they are hostile, but upon completion, they do not fire and appear friendly. They do not move or in any way pursue the player. Once fired upon, or more preferentially a well placed grenade, they do become hostile and return fire. They have the player's bounty on their bodies. (confirmed Xbox 360 and PS3)
 * If the player has access to the Regulator HQ and murders all of its Regulator inhabitants, Sonora Cruz will still remain friendly towards you and act as if nothing has happened. (confirmed all platforms)
 * Sometimes Giant Radscorpions, Deathclaws or Sentry Bots will spawn nearby and scare off Sonora Cruz. Killing said mutated creature will usually force her return. (confirmed all platforms)
 * If you murder the regulators (IE via the sandman), then attack Sonora Cruz, she may runaway never to return, or despawn, thus making the on going quest and the perk void.
 * Sometimes when creatures spawn in the HQ Sonora will run outside and never come back inside the HQ but will be outside and you will still be able to sell fingers to her (confirmed all platforms)
 * If the above bug happens, and if an enemy spawns outside the HQ and attacks, Sonora can run away and "despawn", again making the sub-quest and perk unavailable.

Behind the scenes

 * Regulator is the actual term for an official who maintains control and supervision of an area of public interest. As a result, many armed groups, both vigilante and official, have been named "Regulators" throughout American history.

Appearances in games
Sonora's Regulators appear only in Fallout 3.