Officials from the nation's top four intelligence and law enforcement agencies urged the Senate Intelligence Committee on Wednesday to support section 702 of the Foreign Intelligence Surveillance Act, which expires this year and is at risk of not being reauthorized after Republican complaints about leaks against the Trump administration.

That section of the FISA allows the intelligence community to get warrants to conduct surveillance on foreign targets outside of the U.S., but privacy advocates have raised concerns about occasional illegal use, and have argued that Americans are sometimes incidentally swept up in some of the ongoing, legal surveillance.

All of the four panelists – Acting FBI Director Andrew McCabe, ODNI Director Dan Coats, Deputy Attorney General Rod Rosenstein, and NSA Director Admiral Mike Rogers – gave examples of how the foreign surveillance tools help the national security work they are all tasked with.

"I could not generate the same level of insight the nation, our friends, our allies around the world count on with respect to counterterrorism, counterproliferation," Rogers said when asked what would happen if 702 were allowed to expire.

"In the absence of Section 702, the Department of Justice and the intelligence community in every case in which we wanted to obtain foreign intelligence information to collect against a particular target, we'd be required to obtain a court order, it would need to be supported by probable cause," Rosenstein said. He added that such a legal shift would be enormously time consuming.

Rogers added that the nation knows much of what it does about Russia's meddling in the 2016 election because of the law.

Senator Ron Wyden, D-Ore., argued to Coats that the intelligence community must be able to create a metric on the number of Americans who have been accidentally swept up in FISA activities, even if that metric is only some kind of statistical sampling. But Coats argued it wasn't feasible to create that sort of metric.

On Tuesday, a number of Republican senators, including committee member Tom Cotton, R-Ark., introduced legislation that would make section 702 permanent. That drew criticism outside of the committee hearing from fellow GOP Senator Lindsey Graham, R-S.C., who said the law shouldn't be renewed until leakers within the intelligence community are investigated.

"As big a fan as I am of incidental collection, I'm not going to reauthorize a program that could be politically manipulated," Graham said Tuesday.