In an unprecedented move, the Federal Trade Commission has taken legal steps to shut down a Web hosting provider in Northern California that the agency says was directly involved in managing massive global spam operations.Sometime on Tuesday, more than 15,000 Web sites connected to San Jose, Calif., based Triple Fiber Network (3FN.net) went dark. 3FN's sites were disconnected after a Northern California district court judge approved an FTC request to have the company's upstream Internet providers stop routing Internet traffic for the provider.