The question of whether the government has the right to compel the tech company to help uncover what’s inside one of the San Bernardino shooter’s phones has sparked hot debate, with tech companies largely siding with Apple, writing friend of the court briefs in support of privacy and security.

But on Thursday the San Bernardino County district attorney wrote a letter of his own to the court. Michael Ramos filed a friend of the court brief arguing that there might still be a threat hiding inside shooter Syed Farook’s iPhone. Ramos says the phone was a work phone issued by the health department and could be connected to the county computer network. He claims it could use that connection to potentially introduce a virus into the county system, what he’s calling a “dormant cyber pathogen.”

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But iPhone expert Jonathan Zdziarski tells ars technica “the world has never seen what he is describing coming from an iPhone.”

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Twitter, Facebook, Google, Microsoft, Yahoo, Amazon, and dozens of other tech companies all signed on to friend of the court briefs declaring their support for Apple (AAPL) on Thursday. And the husband of a San Bernardino shooting victim also put his support behind Apple, saying a verdict in favor of the FBI could be “abused all over to spy on innocent people.”

Oral arguments in the case begin March 22.