Nobody read the article and now everyone is angry and scared at the big evil psychologist.

It focuses on what's hapenning in the US and capitol events.

"As the United States grapples with a surge of domestic extremism—including the Capitol breach on January 6—psychologists are identifying factors that are at the root of such violence, along with ways to stop it."

And here is the full quote about anti capitalism

Studies of domestic terrorism have largely focused on three categories: far right, far left, and Islamist. START’s Profiles of Individual Radicalization in the United States (PIRUS), a database of 2,226 people who engaged in extremist crimes, points to some demographic differences between those groups [...] Left-wing extremists include groups and individuals who oppose capitalism, support environmental or animal rights causes, or embrace communism, socialism, or anarchism (The Escalating Terrorism Problem in the United States, Center for Strategic and International Studies, 2020). Some members of the anti-fascist political protest movement Antifa have enacted violent extremist crimes, but research by psychologist Gina Scott Ligon, PhD, director of the National Counterterrorism Innovation, Technology, and Education Center (NCITE) at the University of Nebraska Omaha, shows that while Antifa-inspired individuals engaged in increasing levels of violence over the summer of 2020, it is still a decentralized movement with low levels of coordination and does not meet the criteria for an organization (Dynamics of Asymmetric Conflict, Vol. 14, No. 1, 2021).

So if ou want a take home message it's that violence define radicalization.

Radicalization of opinion can be an important precursor to meaningful social change,” said Lemieux. “The problem is when people begin to feel that using violence in service of those views is not only justified but also recognized and celebrated.”

Source : https://www.apa.org/monitor/2021/07/cover-domestic-extremists