In the anxious months after the Sept. 11 attacks, the National Security Agency began sending a steady stream of telephone numbers, e-mail addresses and names to the F.B.I. in search of terrorists. The stream soon became a flood, requiring hundreds of agents to check out thousands of tips a month.
But virtually all of them, current and former officials say, led to dead ends or innocent Americans.
F.B.I. officials repeatedly complained to the spy agency that the unfiltered information was swamping investigators. The spy agency was collecting much of the data by eavesdropping on some Americans' international communications and conducting computer searches of foreign-related phone and Internet traffic. Some F.B.I. officials and prosecutors also thought the checks, which sometimes involved interviews by agents, were pointless intrusions on Americans' privacy.
As the bureau was running down those leads, its director, Robert S. Meuller III, raised concerns about the legal rationale for the eavesdropping program, which did not seek court warrants, one government official said. Mr. Mueller asked senior administration officials about "whether the program had a proper legal foundation," but deferred to Justice Department legal opinions, the official said.
Even as we are seeing more and more implications of little or no legal basis for warrantless spying on Americans, it is difficult to tell if Congress will put its partisan duties aside and take up its constitutional duty to check the executive. Let's hope they will.