The US Department of Justice is reportedly trying to have Facebook break the end-to-end encryption of its popular Messenger chat app so that the government can spy on a suspect’s “ongoing voice conversations” in a criminal investigation related to the notorious MS-13 gang. Facebook has so far pushed back against the DoJ’s request, according to a new Reuters scoop on the situation.

End-to-end encryption makes it so that only the participants of a conversation can see the messages and content that it contains. Facebook does not have access to the data.

Reuters says that the surveillance case is under seal in California, so no documents or information about it are publicly accessible. And it seems like tensions are rising fast: earlier this week, the government reportedly sought to hold Facebook in contempt of court for refusing to comply with its demands. Facebook’s position is that it would either have to remove encryption from Messenger altogether or “hack” the individual that the government wants to listen in on. Right now, the company seems unwilling to do either.

The conflict is similar in principle to Apple’s standoff with the FBI

The standoff is not unlike the public spat between Apple and the FBI that began when authorities ordered the iPhone maker to help them break into a phone belonging to one of the perpetrators of the 2015 San Bernardino, California shooting. Apple refused, arguing that helping the FBI skirt its end-to-end encryption would have perilous privacy consequences for millions of consumers. Before that dispute could make it to court, the FBI found a third party to unlock the San Bernardino iPhone and dropped the case.

In this instance, the government is “seeking a wiretap of ongoing voice conversations by one person on Facebook Messenger,” according to Reuters. By refusing to assist in a case that involves MS-13, Facebook could quickly find itself in a heated political conflict — and potentially draw the ire of President Trump. Trump has cited MS-13’s US presence and violent crimes as the direct result of what he says is a broken US immigration system. Trump harshly criticized Apple during the San Bernardino saga and even called for a boycott of the company’s products.

Should Facebook ultimately be forced to compromise Messenger’s encryption, it would set an alarming precedent that could have serious implications for privacy-minded apps like Signal.

Facebook Messenger isn’t end-to-end encrypted by default.

Messenger’s regular conversations are not end-to-end encrypted. But the app has a Secret Conversations feature that, when enabled, can secure chats under strong encryption. Facebook says “a secret conversation in Messenger is encrypted end-to-end, which means the messages are intended just for you and the other person — not anyone else, including us.”

Aside from text, Secret Conversations support photos, videos, and audio snippets. Presumably the latter is what the Reuters story refers to (though it doesn’t specify) and what the government wants to wiretap, as there’s no way to make a proper voice call in a Secret Conversation; those are only available in standard chats.