Alan Chvotkin, executive vice president of the Professional Services Council, said the Snowden case shouldn't affect the way contractors do business. The group represents defense and intelligence contractors, including some in Maryland.

"We're hoping that this is not viewed as a contractor issue," he said. "This should have nothing to do with the fact that this work happened to be done by a contractor."

Stewart Baker, a former assistant secretary for policy at the Department of Homeland Security and now a partner at Steptoe & Johnson, said contract employees may need to be made more aware of internal channels for whistleblowing.

"We might want to ask the question, 'Are we sure that contractor employees have the same sense of the importance of their mission and the opportunities to raise concerns inside the system that are widely available to government employees?' " he said.

John Pike, director of GlobalSecurity.org, a military-information website based in Alexandria, Va., said he hopes the NSA leak prompts the government to revisit the way it processes security clearances — for both contractors and federal employees.

He suggests the government needs to ask more questions up front, "and then keep asking those questions" afterward to catch troubling changes.

"They gave too many people clearances a decade ago, after Sept. 11, because the defense budget doubled and the intel budget more than doubled," he said. "They were giving clearances to people who have no business having clearances. They still have them."

Steven Aftergood, director of the Project on Government Secrecy at the Federation of American Scientists, said it is premature to devise policy changes. It's not yet clear, he said, whether the case speaks to a broader problem with the way clearances are issued or whether any screening would have flagged Snowden.

"People are going to want to have a better understanding of exactly how the Snowden case transpired," Aftergood said. "These are questions that will need to be sorted through."

Baltimore Sun reporter Matthew Hay Brown contributed to this article.

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