FBI Director Kash Patel said Monday that he had opened an investigation into the Signal group text chats that Minnesota residents are using to share information about federal immigration agents’ movements, launching a new front in the Trump administration’s conflict there with potential free speech implications.

Patel said in an interview with conservative podcaster Benny Johnson that he wanted to know whether any Minnesota residents had put federal agents “in harm’s way” with activities such as sharing agents’ license plate numbers and locations.