Text on computer screens is not suspended in some parallel universe. Computer text does exist in some type of very real, though invisible, memory - RAM, ROM or cache. And, as Luca Toschi says, even if we link texts, each of those computerized texts will have an author and a copyright. As for authorship, surely the last 20 years of postmodern critical theory have done enough to discredit notions of closure that try to privilege authors' interpretations of their texts. As a reader, teacher, literary critic, author and publisher, I have yet to see any author control a reader's interpretation.
Closure is an illusion, albeit a necessary one for texts.
Cyberspace will not destroy the concept of authorship and texts as legal entities. Just read those dire warning labels about copyright infringement on the latest web page you surfed or on that software you just bought. Geoffrey Nunberg sees hypertext leading to a loss of quality information because he thinks criteria for publishing on the Internet is not controlled as well as it is by established publishing norms. But, I don't think removing control of publishing from the hands of a few communications conglomerates, whose bottom line is money, is such a terrible thing. Sure, a lot of junk will get published on the Internet.