It’s not illegal to send an email telling Immigration and Customs Enforcement (ICE) officials that their actions will haunt them, a federal judge ruled Tuesday, granting a preliminary injunction that blocks ICE from threatening to prosecute a critic for protected speech.

Back in January, David Streever sent a scathing three-paragraph email to then-acting director of ICE, Todd Lyons. Outraged by the killings of two Minnesota protestors against ICE, Renee Good and Alex Pretti, Streever told Lyons that he was a “monstrous human being” who will eat himself “alive with shame” for defending officers who shot people who posed no threat and had no weapons. Comparing Lyons to an infamous high-ranking Nazi cop, Streever predicted that “even Trump” would one day turn on Lyons for defending the “obvious” slayings of Americans.

“You are a monstrous human being and will go down in history as America’s Reinhard Heydrich, the butcher,” Streever wrote. “You will never know peace. You will seek to lose yourself, to escape the burden of knowing the truth about yourself. But wherever you go, you will find yourself. You will torment yourself until your last day on Earth.”

ICE did nothing when the email was received, but five months later, the agency served a warning notice at Streever’s home that claimed his note may have constituted a criminal threat of violence.

Those warnings are normally issued to people threatening to assault, kidnap, or murder officials, not morally condemn their actions. But ICE held Streever’s email to the same bar, warning that if he did not “discontinue” speaking critically of ICE leadership, he risked state and federal prosecution.

Because Streever wasn’t there at the time of their visit, agents took the extra step of tracking him down at a hotel. That “greatly alarmed” him, his lawyers at the Foundation for Individual Rights and Expression (FIRE) said in a press release. And he’s been self-censoring ever since, fearful of government retaliation.