n. A person who uses digital tools and techniques to avenge a crime.
2011
I certainly wouldn’t diminish those with real talent and ability by calling myself a hacker; I was a cyberdouche at best. I say this only to illustrate that I know where the self-professed digilantes of our day—the kids who spam your chat rooms, flood your Minecraft worlds, and cripple your web servers for sport—are coming from.
2010
Sci-fi/fantasy celebrities like Wil Wheaton and Neil Gaiman joined the chorus against Cooks Source, turning the small viral outbreak into a full-blown meme epidemic. Within 48 hours of the story's release, digilantes had compiled a document listing over 150 alleged cases of misappropriation, plagiarism and copyright infringement against Cooks Source magazine.
1998 (earliest)
Other computer wizards have become cult figures after rushing to defend their idea of Internet purity, for example, when several hacker "digilantes" sabotaged Cyber Promotions, Inc., one of the most hated e-mail advertisers, or "spammers."
I should also note an artists collective called The Digilantes that was formed in 1984 with a mission to "embarrass art galleries and academia about digital art — to show them their own aesthetic palette was limited" (Wired).