The case arose when animal rights activists repeatedly posted comments challenging NIH programs which tested drugs or medical procedures on animals. NIH used keyword filters to automatically block all comments containing words such as “animals,” “cruelty,” “monkeys,” “testing” and “torture.” But the U.S. Court of Appeals for the D.C. Circuit said NIH had not articulated “some sensible basis for distinguishing what [comments] may come in from what must stay out,” and its lack of sensitivity to the context of public comments “reinforces its unreasonableness.”

The ruling issued this week creates more new law in the area of how restrictive government entities can be when running a social media page. But the law could change again if the government appeals the case and the Supreme Court rules differently.

NIH declined to comment on the ruling or say whether it would appeal.

Stephanie Krent, a staff attorney with the Knight First Amendment Institute who argued the case in April, said the ruling was “a major victory and reaffirms that the First Amendment forecloses government officials and public agencies from muzzling criticism on their official social media accounts.” She said the opinion made clear “that officials can’t censor speech just because they disagree with it — and that’s true whether they delete specific comments or rely on digital tools like keyword blocking to do it for them.”

People for the Ethical Treatment of Animals filed the suit against NIH in 2021 with Madeline Krasno and Ryan Hartkopf, social media users whose comments had been removed from NIH posts. Krasno told The Washington Post in May that she witnessed animal abuse in a monkey research lab at the University of Wisconsin at Madison. She later began posting online about her experiences, only to find that both Wisconsin and NIH were removing her comments.

“It’s time we had an open conversation about all the animal testing you fund,” Krasno wrote on an NIH Instagram post about covid-19. “What a waste of life and resources.” The comment was deleted because it contained the words “animal” and “testing” from the department’s keyword filters.

With the help of the Animal Legal Defense Fund, Krasno sued both Wisconsin and NIH. In both cases, federal district courts ruled against her, including U.S. District Judge Beryl A. Howell in Washington. Howell said the issue was “at the frontier of courts’ application of the First Amendment to the internet,” and found NIH’s content restrictions to be reasonable. Krasno’s appeal of that decision resulted in Tuesday’s ruling; her appeal against Wisconsin is pending

Both the University of Wisconsin and NIH said they were merely trying to keep their social media feeds from being overrun by repetitive, irrelevant comments. Justice Department attorney Jennifer Utrecht argued to the appeals court in April that there was “a seemingly coordinated campaign to flood [NIH’s] social media pages with off-topic commentary related to animal testing.”

But the appeals court ruling issued Tuesday, written by Judge Bradley N. Garcia and joined by judges Karen LeCraft Henderson and Patricia A. Millett, said NIH had not devised “objective, workable standards” for determining what is “on-topic” and what is “off-topic.”

“To say that comments related to animal testing are categorically off-topic,” Garcia wrote, “when a significant portion of NIH’s posts are about research conducted on animals defies common sense.” The right to praise or criticize governmental agents “lies at the heart of the First Amendment’s protections,” Garcia wrote, “and censoring speech that contains words more likely to be used by animal rights advocates has the potential to distort public discourse of NIH’s work.”

Krasno said she was “very excited” by the ruling, and hoped that it could influence not only the pending Wisconsin case but the behavior of universities nationwide. “These universities using our tax dollars can no longer be filtering out comments they don’t want to see,” Krasno said. “We need to be looking at where our public tax dollars are going, if there are better ways to be using it. That conversation should really be at the forefront, and shouldn’t be filtered out.”

PETA Senior Vice President Kathy Guillermo called the ruling a win for transparency, the public, animals and government accountability.

“This landmark decision,” Guillermo said, “reinforces that NIH can no longer ‘distort’ the message to defend its use and funding of cruel, pointless experiments on animals.”