Edward Snowden says that during his time as a contractor with the National Security Agency he raised concerns about the extent of its electronic surveillance, but the NSA's own search of email shows he only asked the agency's legal department for a single "clarification" on a technical issue.

Following a request for internal communication involving Snowden, the NSA told the Senate Intelligence Committee that there is no evidence that he "expressed concerns or complaints, in email or any other form, about NSA's intelligence activities to anyone in a position of authority or oversight."

In an interview with NBC News this week, Snowden, who is living in self-imposed exile in Russia, described himself as a patriot who had no choice but to expose the NSA's illegal spying by leaking classified information to the media.

"I reported that there were real problems with the way the NSA was interpreting its legal authorities," he told interviewer Brian Williams in response to a question about when he first brought his concerns to superiors at NSA.

On Thursday, the intelligence committee's chairwoman, California Sen. Dianne Feinstein, released the unclassified email that the NSA believes Snowden was referring to.

In it, Snowden asks if the NSA's Office of General Counsel can "clarify" his understanding that presidential executive orders may supersede federal laws but may not override those laws.

The Office of General Counsel replies: "Hello Ed, Executive Orders (E.O.s) have the 'force and effect of law.' That said, you are correct that E.O.s cannot override statute."

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