a computer programmer hired to prevent illegal acts such as hacking a forbidden network or sending out a virus or worm; also, a computer expert, usually a former hacker, who now uses his or her skills for legitimate causes; also called white hat hacker
fr its use in western /cowboy movies
computing
: I told them they were the white-hatguys
noun phraseA law-abiding, morally upright, and heroic person, as distinct from the villainous black hat
[1970s+; fr the conventional dress of heroes in cowboy movies]