The agency appears to have come under pressure from the court that oversees its surveillance activities, judging from statements it issued on Friday.
"NSA will no longer collect certain Internet communications that merely mention a foreign intelligence target," a statement from the agency said.
"This information is referred to in the intelligence community as 'about' communications in Section 702 'upstream' Internet surveillance. Instead, NSA will limit such collection to Internet communications that are sent directly to or from a foreign target."
Seems NSA was forced to sacrifice a mass surveillance program (called "about collection") to avoid questions in upcoming 702 reauth battle. https://t.co/Fyz2vjiSsN— Edward Snowden (@Snowden) April 28, 2017
The NSA said further, that though it did not have the ability right now to stop collecting "about" information "without losing some other important data", it would stop the practice "to reduce the chance that it would acquire communications of US persons or others who are not in direct contact with a foreign intelligence target".
"...even though the Agency was legally allowed to retain such 'about' information previously collected under Section 702, the NSA will delete the vast majority of its upstream Internet data to further protect the privacy of US persons communications," the agency said.
Contrary to denials, NSA was in fact sifting through Americans' emails, @Charlie_Savage reports. And now they've been forced to halt it.— Edward Snowden (@Snowden) April 28, 2017
In an accompanying statement, the NSA acknowledged that there had been lapses in surveillance, saying "While the Foreign Intelligence Surveillance Court was considering the government's annual application to renew the Section 702 certifications, NSA reported several earlier, inadvertent compliance incidents related to queries involving US persons information in 702 'upstream' Internet collection.
"Although the incidents were not willful, NSA was required to, and did, report them to both Congress and the FISC."
The NSA said it had self-reported the incidents to both Congress and the FISC. "Following these reports, the FISC issued two extensions as NSA worked to fix the problems before the government submitted a new application for continued Section 702 certification. The FISC recently approved the changes after an extensive review."