Society wants more regulation of tech companies but no one knows how that looks.

In a case in a California federal court, the US Department of Justice wants Facebook to break the encryption of its Messenger app, Reuters reported. The government and tech companies have for years been at odds over privacy considerations, which aim to protect users, but can impede law enforcement investigations.

The case is under a seal, so there are few details available, but unnamed sources told Reuters that it involves an investigation into the MS-13 street gang, an international crime organization and Donald Trump’s favorite bogeyman in immigration discussions. The government reportedly seeks to access a suspect’s voice messages sent through the app. The judge, Reuters reports, heard arguments on Tuesday over whether Facebook should be held in contempt of court for refusing to comply with law enforcement demands.

The decision could have major implications for the tech industry—if the court sides with the government, law enforcement could make similar arguments in the future, rendering encryption and other privacy protections significantly weaker.

Facebook Messenger isn’t automatically end-to-end encrypted for all users—you have to enable a special feature called “secret conversation.”

In a parallel case in 2016, the government took on Apple, which would not unlock the iPhone of the mass shooter in San Bernardino, California. Earlier this year, the DOJ found that the FBI did not exhaust all of its options to access the phone before engaging in a court battle with Apple.

Tech companies routinely comply with government requests for information, and Facebook itself produces some information for nearly 75% of all such requests. But Facebook says that in this case, it would have to re-write the code for the entire app and all its users, Reuters reported, since Messenger communications are encrypted end-to-end, and no one but the sender and addressee can access them. Alternatively, it would have to hack one of its own users, the government’s target.