FBI Director Robert Mueller speaks out against a ruling that blocks what the Bush administration considers a key tool in its war against terrorism. The tool involves so-called "National Security Letters." The government sends these letters to companies like Internet service providers to obtain e-mail addresses and telephone numbers — without approval by a judge. Consumers don't even know their records have been passed along. The ACLU filed suit against the procedure. And in September, a New York district judge agreed. The government appealed that decision earlier this week. Mueller said National Security Letters are needed to effectively gather information.