Last year, two federal investigators showed up at David Streever's home in Rochester, New York, while he was away. They left a "warning notice" that accused him of possibly breaking federal law and warned that his "criminal activities" would count against him going forward, according to the notice reviewed by Reason. His offense: sending an angry email to Todd Lyons, then the acting director of Immigration and Customs Enforcement, after ICE agents fatally shot a protester in Minneapolis. Streever called Lyons "a monstrous human being" and compared him to a notorious Nazi official, according to the email cited in his lawsuit. He never threatened anyone.

That didn't stop federal agents from trying to intercept Streever at JFK Airport as he returned from a trip abroad with his 7-year-old daughter, then following him to his hotel. Investigators eventually closed the case without ever managing to interview him or establish that he posed any actual threat.

Now, fighting Streever's First Amendment lawsuit, government lawyers have conceded in court filings that his email simply "put words to his disagreements with a current administration official." In plain terms, federal officials have admitted, in their own defense, that they investigated a private citizen for exercising a constitutional right.

Streever's attorneys, from the nonpartisan Foundation for Individual Rights and Expression, say his case isn't unique. Other ICE critics reportedly have received similar visits, and separate reporting describes a large-scale effort to track online criticism of the agency. Whatever anyone thinks about immigration enforcement, no federal agency should be allowed to use its investigative power to intimidate the people who criticize it.

Sign the petition to demand ICE and the Department of Homeland Security stop investigating Americans for protected political speech, before another family gets a knock at the door over an email.