WASHINGTON/LOS ANGELES (Reuters) — The U.S. Department of Justice filed a motion seeking to compel Apple Inc to comply with a judge’s order for the company to unlock the iPhone belonging to one of the San Bernardino shooters, portraying the tech giant’s refusal as a “marketing strategy.”

The filing escalated a showdown between the Obama administration and Silicon Valley over security and privacy that ignited earlier this week.

The Federal Bureau of Investigation is seeking the tech giant’s help to access the shooter’s phone, which is encrypted. The company so far has pushed back, and on Thursday won three extra days to respond to the order.

Apple did not immediately respond to a request for comment.

The motion to compel Apple to comply did not carry specific penalties for the company, and the Justice Department declined to comment on what recourse it was willing to seek. In the order, prosecutors acknowledged that the filing “is not legally necessary.”

But the Justice Department said the motion was in response to Apple CEO Tim Cook’s public statement Wednesday, which included a refusal to “hack our own users and undermine decades of security advancements that protect our customers.”

The confrontation has pitted privacy advocates, who do not want to give any ground to government efforts to undermine encryption, against law enforcement officials who say people’s lives may be at stake unless the shooter’s iPhone is unlocked.

A federal court hearing in California has been scheduled for March 22 in the case, according to Thom Mrozek, a spokesman for the U.S. Attorney’s Office for the Central District of California.

“Rather than assist the effort to fully investigate a deadly terrorist attack … Apple has responded by publicly repudiating that order,” prosecutors wrote in the Friday order.

“Apple’s current refusal to comply with the court’s order, despite the technical feasibility of doing so, instead appears to be based on its concern for its business model and public brand marketing strategy,” prosecutors said.

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