The Supreme Court is set to decide whether it will hear a legal challenge to a controversial National Security Agency surveillance program.

The justices met Friday to consider a petition from the Electronic Privacy Information Center (EPIC) to overturn the NSA’s program to collect records on all U.S. phone calls.

The court is likely to announce on Monday whether it will take up the lawsuit. In most cases, four justices must vote to consider a case.

Other civil liberties groups such as the American Civil Liberties Union and the Electronic Frontier Foundation are also mounting legal challenges to the NSA programs disclosed by Edward Snowden. But EPIC’s challenge is the only one to go directly to the Supreme Court.

EPIC’s suit claims that the Foreign Intelligence Surveillance Court (FISC) overstepped its authority when it granted the NSA permission to collect the phone records in bulk.