“Given this administration’s poor track record of distinguishing protected speech from criminal conduct, any investigation like this deserves very close scrutiny,” he said.

For months, digital tools have been at the center of how people have pushed back against immigration enforcement efforts in Minnesota and across the country. The administration’s opponents have used group text chats to track Immigration and Customs Enforcement operations, share photos of suspected ICE vehicles and raise awareness for neighbors. In June, administration officials criticized ICEBlock, an app designed to share information about ICE sightings. Apple removed the app from its app store in October, prompting a lawsuit from the app’s developer alleging the administration unlawfully pressured Apple to remove it.

In the past few days, the group text chats — especially those on the encrypted messaging app Signal — have drawn attention from right-wing media. On Saturday, Cam Higby, a conservative journalist based near Seattle, said in a thread on X that he had “infiltrated” Signal groups from around Minneapolis that he alleged were obstructing law enforcement. His thread, which got 20 million views, focused on how the groups share such information as the license plate numbers of suspected federal vehicles. NBC News has not verified Higby’s claims.

Patel said he got the idea for the investigation from Higby.

“As soon as Higby put that post out, I opened an investigation on it,” he said. “We immediately opened up that investigation, because that sort of Signal chat — being coordinated with individuals not just locally in Minnesota, but maybe even around the country — if that leads to a break in the federal statute or a violation of some law, then we are going to arrest people.”

The Signal Foundation, the nonprofit organization that operates the Signal app, did not immediately respond to a request for comment.

Signal, which is considered one of the most secure chat apps, is a go-to resource for people concerned about privacy. It is perhaps best known as the app Defense Secretary Pete Hegseth used to share sensitive military information last year in a group chat that accidentally included a journalist.

In the Twin Cities, Signal group chats have been a standard part of toolkits — along with walkie-talkies and whistles — used by activists, parents and neighborhood-watch members who have organized as volunteers to warn families about immigration enforcement activities by relaying real-time information, especially near schools. Patrol volunteers have said that, with more than 3,000 federal immigration agents in Minnesota, they are motivated by a desire to protect parents, children and school staff members who are not U.S. citizens.

Patel did not say which laws he thought Minnesota residents may have violated. An FBI spokesperson said the bureau had no further information to provide.

The announcement seemed likely to have implications for the First Amendment’s guarantee of free speech. Alex Abdo, litigation director at the Knight First Amendment Institute at Columbia University, said the First Amendment protects the right to record law enforcement officers as they carry out their official responsibilities.

“The ability of everyday citizens to hold government agents to account, by observing them and advocating for change, is what has distinguished the American experiment with democracy from authoritarian regimes around the world,” Abdo said in an email.

“Unless the FBI has evidence of a crime, and not just evidence of activity the Constitution protects, it should stand down,” he said.

Patel acknowledged in the interview with Johnson that an investigation into group text chats would raise free speech concerns and said the FBI would “balance” the rights guaranteed by the First and Second amendments with what he said were potential violations of federal law.

“Now, we will balance the First and Second amendment constantly, but we have to let the community know that we will not tolerate acts of violence and an escalation and a violation of the federal code,” he said. The Second Amendment could be at issue because Alex Pretti, the nurse shot and killed by a federal agent Saturday in Minneapolis, was permitted to carry a gun in public and had one with him.

Terr, of the Foundation for Individual Rights and Expression, said the government does not get to “balance” the First Amendment against its other interests.

“The Constitution takes precedence over any conflicting state or federal law, and over any official’s desire to suppress speech they dislike,” he said in his email.

He added: “There is a First Amendment exception for speech intended and likely to provoke imminent unlawful action, but that doesn’t apply to just any speech the government claims puts officials in harm’s way. By contrast, if individuals are threatening federal agents or conspiring to physically harm them, that is illegal. But conspiracy requires an agreement to commit a specific crime and a substantial step toward carrying it out.”

Patel also said the FBI had made “substantial progress” in an investigation into groups and people responsible for funding resistance to immigration enforcement. He alleged that the protests and neighborhood monitoring are “not happening organically” but did not immediately provide evidence.