Despite the government shutdown, Congress is calling on the Federal Communications Commission to explain why mobile carriers are still selling customer location data.

On Friday, Rep. Frank Pallone, who chairs the House Energy and Commerce committee, asked FCC Chair Ajit Pai for an "emergency briefing" on why the agency hasn't stopped wireless carriers from selling customer's real-time location information. He made the request in a letter (PDF).

The request for an emergency briefing comes three days after Motherboard reported T-Mobile, AT&T, Sprint and other carriers were allowing third-party data aggregators to sell the sensitive information. On Thursday, AT&T and T-Mobile said they would end sales of location data by March, and Verizon said it was phasing out its last four partnerships.

Pallone is asking for a meeting on Jan. 14, even if the government shutdown isn't over by then. The shutdown, which began Dec. 22, has disrupted services at all federal agencies, including the FCC. Pai canceled his CES appearance because of the shutdown.

Despite the disruption, Pallone said the issue was a public safety and national security concern. The committee couldn't wait for the government to reopen to get answers, he said.

"The FCC once again appears to have dragged its feet in protecting consumers," Pallone said in the letter. "While some carriers have now recommitted to stopping such unauthorized disclosure, the public can no longer rely on their voluntary promises to protect this extremely sensitive information."

Several lawmakers, including Sens. Mark Warner, Kamala Harris and Ron Wyden, have also called for the FCC to investigate this practice. 

The FCC didn't respond to a request for comment.

Mobile carriers collect your phone location data and often use it for legitimate services, like roadside assistance and finding lost devices. They also provide this data to advertisers and sometimes lose control of it to third parties.

Phones can often show your location with pinpoint accuracy, as well as your travel history, allowing anyone with access to find your home, your workplace and other areas you frequent.

Some mobile carriers have promised to end this practice by March, but lawmakers are skeptical. AT&T, Sprint and Verizon made a similar promise last June, but recent developments showed that people could still obtain anyone's location data.

After AT&T made its announcement on Thursday, Wyden said in a statement, "I'll believe it when I see it."

Pallone, a Democrat from New Jersey, also expressed his skepticism. He's calling on the FCC to make sure these companies make good on their promise.  

"The FCC must take immediate action to ensure no wireless carrier is allowing the rampant disclosure of real-time location data, and take enforcement action against carriers that violated the Commission's rules and the trust of their customers," Pallone said.

You can read the full letter here:

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