Let’s Talk About Anonymous Versus ISIS by Robert Hackett @FortuneMagazine November 22, 2015, 12:52 PM EST E-mail Tweet Facebook Linkedin Share icons Let’s talk about Anonymous versus the self-identified Islamic State. Last week the former—a dispersed and mercurial hacker outfit—declared “cyberwar” on the latter, seeking retribution for the terror organization’s recent massacre in the French capital. Since then, the gang of digital vigilantes has been collating what it deems to be ISIS-affiliated websites, pummeling them with salvos of Internet traffic in order to take them offline. The mission: silence Islamist propaganda. I have watched with fascination as these combatants clash. The social media prowess of the two groups astounds. Both are insidious masterminds of marketing; their propensity to propagate their ideas is unparalleled, like a tweaked viral strain setting off a pandemic. Odd as it may sound, outreach offices within the U.S. government could probably learn a thing or two from them. During the Russo-Ukrainian crisis, Russian websites like the social media network, VKontakte and the blogging platform LiveJournal have served as effective megaphones for regime propaganda. As an aside, it has been interesting to witness VKontakte creator Pavel Durov—the so-called Mark Zuckerberg of Russia—clamp down on pro-ISIS public channels on Telegram, the encrypted messaging app he founded after his exile from the country as well as his former company. (He had been booted from the CEO role after refusing to obey the requests of Vladimir Putin and his cronies.) These new fora for public opinion and debate not only disseminate our words, they shape the way we think. Anonymous spawned in the hive mind of 4chan, an online image board frequented by the hacker set. ISIS has proliferated its views and violence through Twitter and other digital means—using armies of bots and trolls to spread messages of hate and fear. The Internet—while presenting an incredible opportunity to unite the world, bringing cultures closer together than ever before—also presents a subversive threat in letting the vitriol run wild. A version of this post titled “Anonymous vs. ISIS” originally appeared in Data Sheet, Fortune’s daily tech-business newsletter. Subscribe here. Follow Robert Hackett on Twitter at @rhhackett, or keep up with his cybersecurity, technology, and business coverage here. For more about Anonymous versus ISIS, watch this Fortune video.