This was Markos’ attempt to support Shaun King who writes for Daily Kos, but whose lies were exposed by Breitbart.
The man arrested was a man named Joshua Ryne Goldberg, who actually wrote for many leftist rags, including, oh my, Daily Kos, where he was a contributor in one of his many personalities. Markos links to the Daily Beast article which actually says this, but here’s a shot of the contributor byline as well, when Goldberg was pretending to be a feminist, Tanya Cohen.
Markos not only has a problem of with accuracy and lying, but also having his writers and contributors like Shaun King and Joshua Goldberg being complete fakes.