"The perpetrators of violence posted about attacks on social media are often inspired by the online screeds of others, and are actively involved in internet forums where extremism thrives. From politicians to professors to parents, people have begun speculating about the role of social media in the increased violence. While no one suggests that a single violent video, blog post, or rant causes violence, experts in extremism and organizations such as the Anti-Defamation League and Southern Poverty Law Center have noted that online extremism feeds real-world violence

Extremism: the state of hate -- Social media and extremism: a perfect fit -- Is extremist speech against the law? -- Should government regulate extremism on social media? -- Are social media companies the solution to online extremism?.