Last month, J.K. Rowling sued some of her fans over their efforts to transform the “Harry Potter Lexicon” from a website into a book, arguing that what they called a reference work was an infringement of her intellectual property rights. (Although many observers would say that the real impetus for the suit comes not from Rowling, but from her co-plaintiff, Warner Bros.) Now Stanford University’s Fair Use Project is coming to the defense of RDR Books, the company that seeks to publish the lexicon, by agreeing to serve as the imprint’s co-counsel. Fair Use Project executive director Anthony Falzone will be joined on the case by associate director Julie Ahrens and Lawrence Lessig, the author of Free Culture and a hero to many in cyberspace for his advocacy of looser restrictions on copyright. Ex-federal prosecutor David Hammer remains the lead counsel for RDR in the suit.