The online left goes to war: Stefan Bertram-Lee was an internet leftist. And then they went to Rojava [Northern Syria / Western Kurdistan] and got a gun

Bertram-Lee grew up, in their own terms, “extremely online.” They credit long hours on anarchist Reddit groups with a political awakening... It was in university that Bertram-Lee joined a small anarchist group, and in the summer of 2014, after their first year, they found themselves browsing the Syrian Civil War Wikipedia page, trying to make sense of the various forces involved in the struggle... “Öcalan’s the greatest philosopher of the twenty-first century,” Bertram-Lee says. “Not that there is a lot of competition.” But it was only after the siege of Kobanî that Bertram-Lee decided to take the plunge and join up.
...
After a crossing involving Peshmerga helicopters and a tense standoff with border guards, they made it to the training camp. There Bertram-Lee learned how to live a highly structured life under the YPG’s unique blend of ideologies, calling it “a strange mix of libertarianism and authoritarianism.”
...
“The YPG commanders were very clear with us that the numbers of Western volunteers was never going to be enough to make a difference in the war. That while the help is nice, one of the main reasons that they invite volunteers is so you can come to Rojava, become a much superior revolutionary through political education and the real experience of revolutionaries living communally and solving issues together. And help Rojava by going back to their own countries and working to transform them like Rojava has been transformed.”

Online radicalization is usually thought of as a right-wing or fanatical-religious phenomenon but this is an example of how it can happen on the left too. This article shows how someone can go from Reddit and other influences, to crossing into Syria to take up arms for a political cause, to eventually coming back to the West after being trained and educated by a militia with the express purpose of spreading their ideology via western fighters returning from abroad.