There is a relevant chapter in the original (1972) Revolting Librarians, edited by Celeste West and Elizabeth Katz: "Free Libraries and Other Ways to Fly" by Elizabeth Katz.

You might want to take a look at Activism in American Librarianship, 1962-1973, edited by Mary Lee Bundy and Frederick J. Stielow, though it doesn't really talk about radical libraries (it's primarily about activism from within the American Library Association).

Since you're in Montreal (McGill GSLIS is my alma mater!), you should of course mention the local anarchist library, DIRA, never mind the academics!