Feds used Signal access to build Minnesota case

Feds used – Federal prosecutors say a case against 15 alleged “anti-ICE rioters” in Minnesota rests largely on more than 100 messages from Signal groups. The indictment points to Signal chats and “connected” calls, but it also leaves a crucial question unanswered: how Hom

For many anti-ICE activists in Minneapolis, Signal wasn’t just another app. It was a way to talk in encrypted group chats and to organize rapidly—helping locals track federal agents moving through their communities.

But this week, the Department of Homeland Security said 15 alleged “anti-ICE rioters” in Minnesota were arrested, and it pointed straight to those Signal communications.

The indictment built in large part from conversations across more than a dozen Signal groups, citing more than 100 specific messages. It also describes other forms of communication tied to the Signal platform—mentioning voicemails. text messages. Signal direct messages. and Signal calls—turning what many believed was private coordination into something prosecutors could lay out in court.

The case has landed as a high-stakes reminder of what encryption can and can’t do once a device is compromised. Signal’s end-to-end encryption protects message contents while they travel over the internet. But the indictment’s details suggest the risk may have come later, at the physical level.

At the center of the prosecution are allegations that the 15 people named in the latest indictment took part in local ICE rapid response networks. Those networks. as described in the indictment. involved volunteers monitoring and reporting the presence of federal agents by flagging details such as the license plate numbers of vehicles used by immigration authorities.

ICE watchers in Minnesota have also faced intimidation from immigration authorities amid national outcry following the killings of Alex Pretti and Renee Good as they observed the actions of immigration authorities.

For the accused, the charges are serious and wide-ranging. All 15 are charged with “conspiracy to impede or injure an officer.” Some also face additional charges, including “solicitation to commit a crime of violence” and “destruction of government property.”

Some of the accused had court appearances on Tuesday, but defense attorneys have not yet been named.

The indictment offers no clear. straightforward answer to how Immigration and Customs Enforcement’s Homeland Security Investigations unit obtained access to the Signal communications. Still. the document includes clues that law enforcement may have gained access to the physical devices of at least some of those indicted.

In one part of the indictment. prosecutors describe how two of the indictees “exchanged approximately 20 connected Signal calls.” That phrasing points to something more than passive observation of group chats. It suggests investigators may have been able to collect more expansive information from the devices themselves.

The federal push into this case did not start in a vacuum. Months earlier, FBI Director Kash Patel said in a podcast interview that federal law enforcement began an investigation into Minnesota ICE watchers using Signal groups to share information about immigration agents.

That timeline matters because it underscores how the government viewed Signal-linked activity from the outset, even as activists relied on the app’s security features.

Signal’s disappearing messages are often presented as one of the app’s strongest safeguards. Messages can be set to expire in periods ranging from seconds to weeks. Users can select a default expiration time for all messages, and set specific groups and conversations to custom retention times.

But disappearing messages do not erase the fact that a conversation happened. Even if a group has enabled disappearing messages. someone who gains access to a member’s device could later determine with whom they were chatting—based on what remains on the device after the fact. For that reason. the practical guidance is that it’s safest to delete entire groups and chats. not just the messages themselves.

Signal also keeps records tied to voice and video calls. The message disappears, but the calls leave traces unless they’re handled intentionally. It also keeps similar records for calls both within the Signal app and in a user’s phone’s standard call history.

On iPhones, Signal can integrate its call history into the iPhone’s regular call history. That feature can be disabled on Signal on iOS by tapping the profile circle at the top-left corner of the app, clicking on Settings, then Privacy, then disabling “Show Calls in Recents.”

On iPhones, the guidance extends further: users are urged to disable settings like “Share Contacts with iOS” and “Use Phone Contact Photos,” which can be found under Settings, then Chats. For Android users, the equivalent is “Use address book photos.”

The fear behind those steps isn’t theoretical. A case described in the source material says authorities were able to recover deleted incoming Signal messages based on old push notifications archived on iPhones. and it notes that the latest iPhone update fixes this issue—making device updates part of the safety conversation.

Even notifications can expose people. The recommendation is to either turn off Signal notifications entirely or have them display only the names of people sending messages—names that should be pseudonyms, not real names.

The indictment against the 15 people named in Minnesota leaves activists and civil liberties advocates with a hard, unanswered question: how did Homeland Security Investigations reach Signal data in the first place?

Prosecutors say the case is built from Signal group transcripts and more than 100 messages. and it includes details about Signal calls and other communications. But by not providing a clear explanation of the access point. the document forces the same conclusion many users dread: encryption can hold while messages move. yet still fail if the wrong hands get to the device holding the history.

Signal ICE Homeland Security Investigations Minneapolis encryption disappearing messages indictment Minnesota Alex Pretti Renee Good Kash Patel