The US District Judge Jeffrey White in San Francisco has ordered the NSA to retain millions of telephone records collected over five years ago and has scheduled a trial on March 19 to decide whether they can be destroyed or not.

The latest ruling comes in wake of an appeal by a privacy group the Electronic Frontier Foundation, which sought a provisional restraining order, stating the data may be used as proof in its proceedings defying NSA’s massive surveillance activities.

White said: "It is undisputed that the Court would be unable to afford effective relief to plaintiffs once the records are destroyed, and therefore the harm plaintiffs face is irreparable."

"A temporary restraining order is necessary and appropriate so that the Court may decide whether the evidence should be preserved with the benefit of full briefing and participation by all parties," White added.

Recently, the US FISC has rejected NSA’s request to extend the existing five-year limit for holding phone metadata, ruling that keeping the records any longer would further breach people’s privacy rights.

Several lawsuits challenging the NSA’s massive snooping activities have been filed by privacy groups, such as the American Civil Liberties Union and the First Unitarian Church of Los Angeles.