Critics pressed Twitter and other tech companies to shun online message board 8chan on Monday, after it was used by a mass shooter to announce an attack for the third time this year.
Employing the hashtag #untwitter8chan, users urged Twitter CEO Jack Dorsey to boot 8chan off the platform.
8chan, which in its verified Twitter profile describes its location as "The Darkest Reaches of the Internet," has become a hotbed for white extremist content.