Is it possible that a spectacularly productive era of Internet-driven innovation will soon end, amid new government and corporate controls cheered by millions of turned-off consumers?

Yes, says Jonathan Zittrain, professor of Internet governance at the University of Oxford, cofounder of Harvard Law School's Berkman Center for Internet and Society, and author of "The Generative Internet," an upcoming article in the Harvard Law Review. Machines clogged with "malware" -- the catchall term for code that infiltrates PCs to steal data, send out spam, or produce pop-up messages -- are already costing billions annually and testing everyone's tolerance, Zittrain says.