A federal appeals court are deciding on whether the National Security Agency's programs that collects millions of Americans' phone records are unlawful, according to The Associated Press.
Since the programs were revealed by former NSA contractor Edward Snowden, several cases have been brought against the agency, the AP reported.
The program sweeps up numbers dialed and length and time of calls but not the content of communications or the locations of cell phones, according to the AP.
NSA argues the program, which aims to search for connections to terrorist groups, is legal, but opponents say it violates U.S. citizens' privacy rights, the AP reported.
The U.S. Supreme Court is expected to take up the issue once several appeals courts weigh in, but only if they produce conflicting rulings, according to The Washington Post. The three-judge panel who considered the government's appeal of Leon's ruling on Tuesday were all appointed by Republican presidents.
The U.S. Court of Appeals for the District of Columbia Circuit is the second appellate court to hear arguments on whether the NSA program is lawful, after a panel in New York heard arguments in a similar case in September, the Post reported.
Three district courts overall have weighed in, with two courts siding with the government, according to the AP.
In December, U.S. District Judge Richard J. Leon found in Klayman's favor and said the "almost-Orwellian" program "almost certainly" violated the American citizens privacy rights, the AP reported.
