Director of National Intelligence Daniel Coats testifies at a Senate Intelligence Committee hearing on the Foreign Intelligence Surveillance Act (FISA) in Washington, U.S., June 7, 2017.
Tomorrow is the main event, with fired FBI Director James Comey delivering some highly anticipated testimony.
The hearing is focused on the Foreign Intelligence Surveillance Act (FISA), though there are likely to be questions involving the firing of former FBI Director James Comey and Russian interference in the 2016 US election.
Takeaway Washington Correspondent Todd Zwillich explains what you need to know.
Critics have called the process under which the Federal Bureau of Investigation and other agencies can query the pool of data collected for US information a "backdoor search loophole" that evades traditional warrant requirements.
Congress is expected to vote on the reauthorization effort later this year before it expires on December 31.
NSA chief Mike Rogers said he's never been directed to do anything illegal or immoral.
In the course of justifying Section 702 as an invaluable tool for counterterrorism and counterproliferation efforts, Director of National Intelligence Dan Coats claimed that agencies have made "herculean" efforts to get a count on how many Americans have been affected, but in spite of those efforts it remains impossible.More news: Comey: Lynch Asked Him to Call Clinton Investigation 'a Matter'
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Coats also argued that the capabilities authorized by the surveillance law have produced a critical stream of intelligence, including information that helped the USA track down and ultimately kill the Islamic State terror group's second-in-command in March 2016.
It should go without saying: if the Intelligence Community is truly anxious about the privacy and civil liberties of ordinary Americans, officials will take the looming Section 702 sunset as an opportunity to give lawmakers the information they need to have an informed and meaningful debate about how government spying programs impact Americans' privacy.
He told the Senate Intelligence Committee that even if he dedicated more resources the NSA would not be able to calculate an estimate, which privacy experts have said could be in the millions.
"We're working on that with the Congress and we'll come to a satisfactory resolution, because we have to", said Ledgett, who has since retired from public service. Trump and his allies have accused the intelligence community of improperly unmasking United States persons, revealing their identities to former Obama administration officials who then allegedly leaked them to the press.
Deputy Attorney General Rod Rosenstein agreed, adding that if the intelligence community needed to get a warrant every time it sought to use Section 702 to target foreigners not on U.S. soil, "it would be very time-consuming" and would hinder intelligence agencies' efficiency.
USA intelligence agencies past year accused Russian Federation of interfering in the 2016 presidential election campaign, allegations Moscow denies.
Reuters reported in March that the Trump administration supported renewal of Section 702 without any changes, citing an unnamed White House official, but it was not clear at the time whether it wanted the law made permanent.