...and I found the Anonymous article I was thinking of.

WIRED, November 2011: "Anonymous 101: Introduction to the Lulz"

https://www.wired.com/2011/11/anonymous-101/

Definitely an interesting read when an article not only gives an overview of 4chan's /b/ at the time, but draws a thread back to things like Laurence Sterne's The Life and Opinions of Tristram Shandy, Gentleman (published in parts from 1759 through 1767).