He also argues for the creation of shorter renewable periods of copyright and a limitation on derivative rights, such as limiting a publisher's ability to stop the publication of copies of an author's book on the internet for non-commercial purposes or create a compulsory licensing scheme to ensure that creators obtain direct royalties for their works based upon their usage statistics and some kind of taxation scheme such as suggested by professor William Fisher of Harvard Law School that is similar to a longstanding proposal of Richard Stallman.