How that happened and what it means for privacy and national security are questions that have induced shudders in Washington and a queasy new understanding of the FBI’s comprehensive access to the digital trails left by even top officials.
FBI and Justice Department officials have vigorously defended their handling of the case. “What we did was conduct the investigation the way we normally conduct a criminal investigation,” Attorney General Eric H. Holder Jr. said Thursday. “We follow the facts.”
But in this case, the trail cut across a seemingly vast territory with no clear indication of the boundaries, if any, that the FBI imposed on itself. The thrust of the investigation changed direction repeatedly and expanded dramatically in scope.
A criminal inquiry into e-mail harassment morphed into a national security probe of whether CIA Director David H. Petraeus and the secrets he guarded were at risk. After uncovering an extramarital affair, investigators shifted to the question of whether Petraeus was guilty of a security breach.
When none of those paths bore results, investigators settled on the single target they are scrutinizing now: Paula Broadwell, the retired general’s biographer and mistress, and what she was doing with a cache of classified but apparently inconsequential files.
On Capitol Hill, the case has drawn references to the era of J. Edgar Hoover, the founding director of the FBI, who was notorious for digging up dirt on Washington’s elite long before the invention of e-mail and the Internet.
“The expansive data that is available electronically now means that when you’re looking for one thing, the chances of finding a whole host of other things is exponentially greater,” said Rep. Adam B. Schiff (D-Calif.), a member of the House intelligence committee and a former federal prosecutor.
In this case, Schiff said, the probe may have caused more harm than it uncovered. “It’s very possible that the most significant damage done to national security was the loss of General Petraeus himself,” Schiff said.
Not the usual boundaries
The investigation’s profile has called attention to what legal and privacy experts say are the difficulties of applying constraints meant for gathering physical evidence to online detective work.
Law enforcement officers conducting a legal search have always been able to pursue evidence of other crimes sitting in “plain view.” Investigators with a warrant to search a house for drugs can seize evidence of another crime, such as bombmaking. But the warrant does not allow them to barge into the house next door.
But what are the comparable boundaries online? Does a warrant to search an e-mail account expose the communications of anyone who exchanged messages with the target?