_Order training and education for FBI field offices that were given expanded authority to issue the letters without headquarters' review. The report said many agents were confused or uncertain about the ground rules and that lawyers weren't required to review requests for the letters. That review is now mandatory.
_Require internal controls and more levels of review so that any privacy breach could be spotted immediately and systemic remedies could be implemented.
Mueller said the bureau dropped its use of "exigent letters" for phone records last May.
But the National Security Letters, he said, are "the bread and butter" of FBI counterterrorism investigations, noting that they'd helped agents develop a case against a former sailor accused of transmitting classified information to a suspected terrorist financier and in uncovering a number of cells supporting al Qaida in the United States. A letter can be issued for information if it's believed to be relevant to an investigation.
Suspicious patterns found in phone records can then lead to a request to a special national security court for a warrant to conduct electronic surveillance.
But Anthony Romero, executive director of the American Civil Liberties Union, said the inspector general's report "confirms our greatest suspicions" and called the findings "the tip of the iceberg."
He noted that the FBI looked at only 293 requests for National Security Letters and, in auditing 77 investigative files, found one or more possible violations in 17 of them, or 17 percent.
Noting that Gonzales has defended warrantless spying as legal, Romero said the attorney general "lacks the credibility, political will and the independence" to remedy the problem.
A separate report by the inspector general on the FBI's ability to obtain library and business records found scant problems.
(c) 2007, McClatchy-Tribune Information Services.