In "an important victory for free speech" and animal welfare, a federal judge on Wednesday struck down Iowa's so-called "ag-gag" law, determining that it violates the U.S. Constitution's First Amendment.

"It has effectively silenced advocates and ensured that animal cruelty, unsafe food safety practices, environmental hazards, and inhumane working conditions go unreported for years."
—Rita Bettis Austen, ACLU of Iowa

The legal groups that brought the case challenging Iowa's ag-gag law and other animal rights advocates celebrated the win in court, which follows similar victories in Idaho, Utah, and Wyoming.

"Ag-gag laws are a pernicious attempt by animal exploitation industries to hide some of the worst forms of animal abuse in the United States," Animal Legal Defense Fund executive director Stephen Wells said in a statement on Wednesday. "Today's victory makes it clear that the government cannot protect these industries at the expense of our constitutional rights."

Ag-gag legislation, which has been enacted and often struck down in several states with sizable agricultural industries, aims to prevent journalists and activists from going undercover at factory farms and other facilities where animals are held for commercial purposes, such as slaughterhouses and puppy mills, to shed light on abuse.

As ACLU of Iowa legal director Rita Bettis Austen explained, in her state—home to an estimated 10,000 factory farms—"it has effectively silenced advocates and ensured that animal cruelty, unsafe food safety practices, environmental hazards, and inhumane working conditions go unreported for years."

Senior Judge James Gritzner of the U.S. District Court for the Southern District of Iowa granted summary judgment (pdf) on Wednesday, declaring that the state's lawyers had failed to show that the law's prohibitions on speech "are actually necessary to protect perceived harms to property and biosecurity," as they had argued.

While conceding that protecting both is important, Gritzner further concluded that the "prohibitions are not narrowly tailored to serve either interest." Additionally, his judgement noted that there were other motivations for implementing the law:

[As] admitted by defendants, some lawmakers also wanted to stop "subversive acts" by "groups that go out and gin up campaigns...to give the agricultural industry a bad name." ...Other statements in the record illustrate that [the law] serves the interest of protecting Iowa's agricultural industry from perceived harms flowing from undercover investigations of its facilities.

Journalist, animal rights advocate, and constitutional lawyer Glenn Greenwald declared in a tweet that the decision was "a huge win for free speech and a free press, and a major—and richly deserved—defeat for the pervasively corrupt agricultural industry, that has tried to use their control over governments to criminalize the exposure of their heinous practices."