The Biden administration has asked Congress to renew a surveillance law that is set to expire at the end of the year. Attorney General Merrick Garland and Director of National Intelligence Avril Haines wrote a letter to congressional leadership Tuesday in support of section 702 of the Foreign Intelligence Surveillance Act. The spy program, which started after 9/11 and was later brought to Americans’ attention in the Edward Snowden leaks, allows the government to collect without a warrant phone calls, text messages, emails, and other data that passes through the U.S. believed to belong to foreigners living abroad.

The National Security Agency gathers information straight from U.S. telecommunications firms and other companies like Google, Meta, Microsoft, and Apple. A bipartisan group of lawmakers have raised concerns about the law’s impact on Americans privacy. Some members of Congress are calling for reforms and more transparency over the program.

“This sweeping surveillance program lacks basic protections for Americans’ constitutional rights,” Sen. Ron Wyden, a Democrat on the Senate Intelligence Committee said. “Although 702 was originally created as a foreign surveillance program, it sweeps up vast amounts of Americans’ private communications.”

The spy program has been used to protect the U.S. from a range of threats including other countries’ attempts at recruiting spies and countries trying to evade U.S. sanctions. It has also been successful at stopping cyber attacks and arms traffickers. Assistant Attorney General Matt Olsen said the spy program allows the U.S. to gather important intelligence on countries like China.

“At this moment, when China is ramping up its aggressive efforts to spy on Americans, we should not, we must not blind ourselves to that threat by allowing this critical authority to expire,” Olsen said.

The law is set to expire at the end of the year if Congress doesn’t act to renew it. The last time section 702 was renewed was in 2018.