"All the useful data has been collected," he said.
The surveillance court and the NSA should be more transparent about the data collected, and the court should publish some of its orders, some panelists said. Part of the reason for concern about the surveillance is that the "searches are done in secret," said Kate Martin, director of the Center for National Security Studies, a civil liberties watchdog group.
But it makes sense that the NSA doesn't broadcast the targets of its surveillance, said Kenneth Wainstein, a former White House homeland security adviser. The surveillance court process, which doesn't include a lawyer arguing against the surveillance, mirrors criminal wiretap requests, he said.
"We trust judges" to scrutinize surveillance requests, he said.
Still, Wainstein said there may be some merit in creating a new role for a public advocate during the surveillance court's process because it may restore some public confidence in the process, Wainstein said.
Wainstein and Steven Bradbury, formerly with the U.S. Department of Justice's Office of Legal Counsel, defended the surveillance efforts, saying they are necessary to protect the U.S. from terrorism. Despite the recent uproar about the programs prompted by leaks from former NSA contractor Edward Snowden, the U.S. shouldn't significantly limit the surveillance because of some "speculative concerns down the road," Wainstein said.
Bradbury questioned the suggestion to include a public advocate in the surveillance court process. The current process is "workable," he said.
Board member James Dempsey, vice president for public policy at the Center for Democracy and Technology, called on privacy advocates to propose concrete ideas for fixing the surveillance process and on defenders to engage in the debate.
"It can't be that everything is perfect," he said to Wainstein and Bradbury. "It can't be that no changes can be made."
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