PSA: Don't tell Western doctors/therapists that you're a Leftist. The American Psychological Association (APA) classifies anti-capitalists, animal rights advocates and environmentalists as terrorists.
But there actually ARE left-wing 'extremists'. I guarantee you've met at least one. They're the ones who always seem to bring everything back around to some sort of armed conflict. They support all of the regular things that leftists support (at least verbally), but have a tendency to fetishize violence and are alllllll about the guns, man. They often express things like 'acceptable losses' and 'wiping the slate clean'. These people DO exist, and they ARE dangerous to the general health and wellbeing of the public. These are the extremists that I think the APA is talking about.
Obviously, this does not mean that EVERY leftist is an extremist or dangerous to people, and I think the APA's statement is very poorly worded.
Can confirm. I have seen leftists proudly display the communo-anarchist Gadsden flag which implies aggression and violence. These are almost always the same leftists who own guns and advocate for violent revolution & punching fascists.
The report says "two thirds [of violent extremists were] from the far right, about a quarter from the far left, and the remainder were driven by religious or 'ethnonationalist' causes". Violent leftists are absolutely real, and no one should pretend they do not exist. Change requires uncertainty, fear, and discomfort, but violence is optional. The ends never justify the means, the ends are the means.