WASHINGTON - The National Security Agency said Friday that some of its analysts knowingly and deliberately exceeded its surveillance authority on occasion over the past decade and that those involved were disciplined.
"Very rare instances of willful violations of NSA's authorities have been found," the agency said in a statement. It said none of the abuses involved violations of the Foreign Intelligence Surveillance Act or the USA Patriot Act. NSA violations of both laws have been highlighted in the leaks of classified information by former NSA systems analyst Edward Snowden.
Two U.S. officials said one analyst was disciplined in years past for using NSA resources to track a former spouse. The officials spoke on condition of anonymity because they were not authorized to speak publicly.
"NSA takes very seriously allegations of misconduct, and cooperates fully with any investigations - responding as appropriate," the agency statement said. "NSA has zero tolerance for willful violations of the agency's authorities."
The Senate Intelligence Committee was briefed this week on the willful violations by the NSA's inspector general's office, as first reported by Bloomberg.
"The committee has learned that in isolated cases over the past decade, a very small number of NSA personnel have violated NSA procedures -- in roughly one case per year," Sen. Dianne Feinstein, the California Democrat who chairs the committee, said in a statement Friday.
"These incidents ... in most instances did not involve an American's information," Feinstein said. "I have been informed by NSA that disciplinary action has been taken, and I am reviewing each of these incidents in detail."
In an interview with reporters last week, the NSA's director of compliance, John DeLong, said the abuses "are taken very seriously."
"When we make mistakes, we detect, we correct and we report," DeLong said.
Obama administration officials and intelligence overseers in Congress have described the FISA and Patriot Act violations as inadvertent. The NSA this week declassified a secret FISA court ruling from 2011 that revealed the agency had inadvertently scooped up, over a three-year period, as many as 56,000 emails of Americans not connected to terrorism.
The agency had reported the gathering of those emails -- they were mixed in with terrorism targets' emails -- to the FISA court and Congress, and was ordered to change the practice.
The NSA also released documents showing that it created a new procedure to separate the bulk caches of emails most likely to contain those Americans' communications, limit access to them and destroy them more frequently than other information the agency gathers.