On Thursday, the National Security Agency and Office of the Director of National Intelligence declassified documents explaining why the NSA has stopped collecting emails and text messages from Americans that mention foreign surveillance targets but are not to or from them ("about" mentions). Last fall, the Foreign Intelligence Surveillance Court had put off reauthorizing the NSA's authority to collect certain intelligence without warrants under Section 702 of the 2008 FISA Amendments Act because, as FISC presiding Judge Rosemary Collyer wrote, an NSA inspector general's report had uncovered "a very serious Fourth Amendment issue" with how NSA agents searched for the names of Americans tied to foreign targets.
When NSA analysts searched "upstream" channels — like switches that emails and texts travel through in and out of the U.S. — they were more likely to accidentally capture purely domestic communications, so the court had blocked the NSA from searching for "about" mentions in upstream searches ("downstream" focuses on the content of email accounts). Most of the time, analysts didn't use those restrictions, the report found. In March, the NSA, with the approval of the Trump administration, stopped all use of "about" searches, a major contraction of the surveillance apparatus put in place after the Sept. 11, 2001, terrorist attacks. In April, Judge Collyer authorized the new system, without "about" searches, and allowed analysts to search upstream channels again.
"The move increased the risk that the program might miss something important it otherwise would have collected," The New York Times explains, "but removed a cloud at a time when the law on which the program is based, the FISA Amendments Act, is about to expire unless Congress extends it."