It's the U.S. law that allows wiretaps without a warrant for surveilling foreign targets. And the U.S. Congress just let it lapse. Sort of. NPR reports:

Each year, the provision is used by American intelligence agencies to collect the electronic communications of hundreds of thousands of foreigners located outside of the United States. The government says that more than 60% of the president's daily intelligence briefing relies on information collected under the authority. The tool officially lapsed at the end of the day on Friday. What happens now?

Intelligence collection under FISA's Section 702 is authorized annually by a federal court — and the law allows for that collection to contin...