The NSA ended one of its contentious spying programs this weekend
It was first brought to public scrutiny after NSA contractor-turned-whistleblower Edward Snowden leaked documents to journalists about the scale of the US government's spying, provoking a global debate over privacy and security.
Though hailed as a hero by privacy activists, Snowden is viewed as a traitor by many in the US establishment, and would face trial if he returned home (he's currently in exile in Russia.)
But his leaks have provoked some political changes.
Key among these is the USA Freedom Act. It means that the NSA is no longer directly collecting millions of Americans' phone records. It actually came into effect this summer - but there was an 180-day grace period. That period ended just before midnight on Saturday, November 28.
If the NSA wants this data, it will now have to apply to a FISA (foreign intelligence service) court to get it from one of the phone companies. Ewan MacAskill, a Guardian journalist who did some of the earliest reporting on Snowden's leaks, describes it as a "first step but a modest one." And he points out a "major" problem for privacy activists: "The reform applies only to phone records. The NSA can continue to harvest bulk communications from the internet and social media."
Reuters reports that the metadata the NSA has hoovered up over the last five years "will be preserved for 'data integrity purposes' through February 29 [2016]."
So the NSA is no longer collecting phone records directly - but it can access them with judicial authorisation, and it will continue to access internet records directly. These are, arguably, even more important than phone records, as people spend ever-more time online. The battle for privacy activists isn't over yet.