On June 10, 2015, Reddit CEO Ellen Pao announces the ban of five subreddits under a new anti-harassment policy, including r/FatPeopleHate (150,000+ subscribers), r/HamPlanetHatred, r/Transfags, r/NeoFAGs, and r/ShitN*ersSay. The backlash is immediate and severe: users flood Reddit's front page with anti-Pao content, new hate subreddits spawn faster than moderators can remove them, and thousands of users migrate to Voat — a Reddit clone marketed as a "free speech" platform with no content moderation.
In August 2015, Reddit follows up by banning r/CoonTown (20,000+ subscribers) and additional racist communities. The pattern repeats: migration to unmoderated platforms.
The deplatforming paradox becomes visible in real time. Research later confirms that banning hate communities on mainstream platforms reduces overall hate speech exposure — users who don't migrate encounter less extremist content. But the users who DO migrate move to platforms with no moderation at all (Voat, 8chan, later Gab and Telegram), where radicalization proceeds without any friction. The median user is deradicalized; the committed extremist is further radicalized in a smaller, more intense community.
This dynamic shapes the next four years of political violence. 8chan — already a haven for those banned from 4chan — absorbs Reddit refugees and becomes the planning ground for the most lethal attacks: the Christchurch massacre (March 2019, posted manifesto to 8chan), the Poway synagogue shooting (April 2019, posted manifesto to 8chan), and the El Paso Walmart massacre (August 2019, posted manifesto to 8chan). The platform fragmentation triggered by Reddit's 2015 bans doesn't create these extremists — but it concentrates them on platforms optimized for producing violence.
Pao resigns as CEO on July 10, 2015, after sustained harassment. She later writes that she was made a scapegoat for policy decisions made before her tenure. The episode demonstrates that platform moderation of radicalized communities triggers the same coordinated harassment campaigns perfected during Gamergate — directed now at the platforms themselves.