David Streever, a US citizen from Rochester, New York, is suing the Department of Homeland Security and Immigration and Customs Enforcement (ICE) after federal officers visited his home to warn him about an email in which he criticised the agency's leadership. Filed on Monday in Washington, D.C., the lawsuit argues that officials violated his First Amendment right to speak out against the government. The case matters because it raises questions about whether federal agencies are using intimidation to deter criticism protected by free-speech rights.

Streever had sent an email in January to Todd Lyons, then the acting director of ICE, following the fatal shooting of US citizen Renee Nicole Good by an ICE agent during an immigration raid in Minneapolis. The email called Lyons "a monstrous human being" and compared him to Nazi leader Reinhard Heydrich, predicting his downfall and disgrace. While Streever was in Finland with his seven-year-old daughter, two officers arrived at his home and handed his wife a "warning notice" stating he "may be in violation of federal law" for sending the message.