CLIFFORD Stoll is a worried man. As one of the original stars of the international computer network, the Internet, he should not throwing his hat in the air at its growth. He was the man who tracked down a German spy ring operating on the Internet and wrote a best-selling book about it. He is as much into computers and their use for communications as anybody. So why is he hitting the alert button in his latest book? Perhaps 'alert' is an understatement given the apocalyptic tones Stoll adopts. He wastes no time about it, either. Is the Internet 'An ostrich hole to divert out attention and resources from social problems?' he asks on page two. 'A misuse of technology that encourages passive rather than active participation?' By page three, he is well into his stride: 'The wave of computer networks . . . they isolate us from one another and cheapen the meaning of actual experience. They work against literacy and creativity. They will undercut our schools and libraries.' From then on, it is all downhill as far as the Internet is concerned. Stoll does not deny that it has opened up fantastic communications possibilities - though nobody knows just how many users it has. Ten million? 20 million? Is that the number of people who actually use it, or just the number who have access to a computer linked to the Net? When technology gets this big, figures go out of the window and rational judgments become impossible. To some adepts, raising questions about the Net is as bad as questioning the virtues of motherhood or sliced bread, if not worse. As a grade one heretic, Stoll has two basic complaints. One is that, as a communications medium, the Internet is simply too slow and unselective: it takes too long to download quantities of information and a lot of what it carries is simply rubbish, put there to please the supplier's vanity regardless of whether it is actually of use or interest to anybody else. In this he is undoubtedly right. By its free-for-all nature, the Internet lacks either an editing function or the commercial discipline which would make people think twice before giving other the doubtful please of picking up their otherwise unpublishable manuscripts or sheer junk mail. It is an open door for pornography or extremist opinions which would not find their way into conventional print media. In the end, this can become very boring, and spending hours sifting through masses of uninteresting material to get to something worthwhile is not the most efficient use of anybody's time. Stoll's second complaint is that far from creating a friendly, interactive world spanning the continents, the system encourages a generation of lonely nerds hunched in front of their screens who put a greater premium on surfing the Net than on normal human contact. He worries about the substitution of virtual reality for real reality, about the screen supplanting communities, about - a particular bugbear of his - libraries spending more on computer equipment than on the information they are meant to preserve. This is all the stuff of a fine pamphlet. Although it is only 248 pages long, including index, Stoll's book seems too long. One gets the point pretty early on, and it is a good point - or collection of points. But he can't stop hammering away at his theme in such a way that one longs for a bit of counter-argument to stem his flow. Like many good pamphlets, this book assumes absolute correctness. Stoll brooks little argument. He likes to state opinion as fact. That, too, can grow annoying. At times, I wanted to ring up some Net nurds and ask them for a counter-view though, as Stoll would point out, they probably wouldn't have understood what I was talking about, and I certainly wouldn't have understood their reply. There is a deeper theme underlying Stoll's polemic, and it goes beyond the libraries he sheds tears for or the amount of junk lumbering round on the Internet. The question is whether, for all their technological magic, the latest communications systems are necessarily the best ways of transmitting information. To come very close to home, are the days of the newspaper drawing to a close simply because print on paper is an old medium and computerised screen information is the late 20th century mode? The answer might be yes if those operating the latest technology had mastered how to do things as efficiently as by the old methods. So far, they haven't, which is why newspapers may be dying for other reasons but not because of the challenge from systems like the Internet which, in theory, should be making them as redundant as the horse and carriage. Stoll has done an effective demolition job - early enthusiasts often make the best critics of how the objection of their devotions have disappointed their original hopes. But his book leaves one wondering when somebody is going to come along and turn the Internet into an efficient, consumer-driven vehicle for information. At the rate things are going, how about next week?