The Cyber Privateer Code
themorgandoctrine.com
themorgandoctrine.com
In the case of state actors or near state actors (think Russia's Internet Research Agency, various Chinese APTs, or even individual companies such as the NSO Group, Cellebrite, FinFisher, Blue Coat, Hacking Team, CyberPoint, L3 Technologies, and Verint), this is somewhat mooted as impunity may provide protection and the overt flagrance of actions may itself be a dimension of the attack, signalling "we can act at will without consequence". There might also be risks in tangling with large organised crime groups.
That said, vigilante justice does have a broad appeal, and makes for a popular trope in fiction.
(I stumbled across this submission whilst checking to see if I could submit it myself ;-)