Error gave FBI unauthorized e-mail access

WASHINGTON — A technical glitch gave the FBI access to the e-mail messages from an entire computer network — perhaps hundreds of accounts or more — instead of simply the lone e-mail address that was approved by a secret intelligence court as part of a national security investigation, according to an internal report of the 2006 episode.

FBI officials blamed an "apparent miscommunication" with the unnamed Internet provider, which mistakenly turned over all the e-mail from a small e-mail domain for which it served as host. The records were ultimately destroyed, officials said.

Bureau officials noticed a "surge" in the e-mail activity they were monitoring and realized that the provider had mistakenly set its filtering equipment to trap far more data than a judge had actually authorized.

The episode is an unusual example of what has become a regular if little-noticed occurrence, as American officials have expanded their technological tools: government officials, or the private companies they rely on for surveillance operations, sometimes foul up their instructions about what they can and cannot collect.

The problem has received no discussion as part of the fierce debate in Congress about whether to expand the government's wiretapping authorities and give legal immunity to private telecommunications companies that have helped in those operations.

But an intelligence official, who spoke on condition of anonymity because surveillance operations are classified, said: "It's inevitable that these things will happen. It's not weekly, but it's common."

A report in 2006 by the Justice Department inspector general found more than 100 violations of federal wiretap law in the two prior years by the Federal Bureau of Investigation, many of them considered technical and inadvertent.

Bureau officials said they did not have updated public figures but were preparing them as part of a wider-ranging review by the inspector general into misuses of the bureau's authority to use so-called national-security letters in gathering phone records and financial documents in intelligence investigations.

In the warrantless-wiretapping program approved by President Bush after the Sept. 11 terrorist attacks, technical errors led officials at the National Security Agency on some occasions to monitor communications entirely within the United States — in apparent violation of the program's protocols — because communications problems made it difficult to tell initially whether the targets were in the country or not.

Past violations by the government have also included continuing a wiretap for days or weeks beyond what was authorized by a court, or seeking records beyond what were authorized. The 2006 case appears to be a particularly egregious example of what intelligence officials refer to as "overproduction" — in which a telecommunications provider gives the government more data than it was ordered to provide.

The episode was disclosed as part of a new batch of internal documents that the FBI turned over to the Electronic Frontier Foundation, a San Francisco nonprofit that advocates for greater digital-privacy protections, as part of a Freedom of Information Act lawsuit the group has brought. The group provided the documents on the 2006 episode to The New York Times.

Marcia Hofmann, a lawyer for the privacy foundation, said the episode raised troubling questions about the technical and policy controls that the FBI had in place to guard against civil liberties abuses.

"How do we know what the FBI does with all these documents when a problem like this comes up?" Hofmann asked.