The trade began with the purpose of finding people using false identities known as a V.I. (Virtual Identity). V.I.s were created as false ids in the digital age. Early on they were often used to create second lives. The advent of V.I.s caused havoc to the banking industry which resorted to technically adept mercenaries referred to as a spy hunter. Once corporate investigators with physical skills in the field, they now have an ominous reputation for killing targets to minimize blowback. The spy hunter guild was established to provide some civility with members no less prone to killing.
Many falsely believe spy hunters often kill for enjoyment. They kill due to the methods they resort to. To extract information that a mark will not give up voluntarily they run a wire through your head which forces the target to speak but it kills the person within minutes. The wire is called a killjoy. The victim is in a euphoric state that you can ask them anything and they give up that information without hesitation. But the form of coercion comes at the price of killing the mark.
Spy Hunters do operate within ethical boundaries established by the spy hunter guild. Only a few of the guidelines have leaked to the public. One guideline all spy hunters honor is they never kill their own. Contracts against fellow spy hunters are strictly prohibited.