The galvanized metal walls of North Carolina’s expansive poultry houses and hog farms received some significant reinforcements against prying eyes on Jan. 1. A new law that critics have labeled an ag-gag measure went into effect that day, making it a criminal act to gain employment at a business for the purposes of an undercover investigation, among other activities pursued by animal rights activists, whistle-blowers, and journalists. On Wednesday, groups representing all those parties filed a federal lawsuit questioning the constitutionality of the legislation.

“This law blatantly violates citizens’ rights to free speech, a free press, and to petition their government, and violates the Equal Protection Clause,” the plaintiffs said in a joint statement. “It places the safety of our families, our food supply, and animals at risk, and it attempts to bully and threaten those working for transparency, free speech, and the public good.”

The plaintiffs include an array of good government, animal welfare, and public health groups: People for the Ethical Treatment of Animals, the Center for Food Safety, the Animal Legal Defense Fund, Farm Sanctuary, Food & Water Watch, and the Government Accountability Project are all party to the suit.

The complaint alleges the law violates both the state constitution and the Constitution of the United States; similar legal challenges, including the one that saw Idaho’s law overturned (although that case has been appealed), have argued that this type of legislation violates federal constitutional rights. According to the suit, the law punishes people “who set out to investigate employers and property owners’ conduct because they believe there is value in exposing employers and property owners’ unethical or illegal behavior to the disinfecting sunlight of public scrutiny.”

Unlike laws passed in other states, North Carolina’s isn’t limited to agricultural facilities.

“It is a broader-spectrum law,” said Amanda Hitt, director of the Government Accountability Project’s Food Integrity Campaign. “It encompasses anything from nursing homes to assisted living, anyplace where you have a vulnerable population that could benefit from a whistle-blower.” The potential for the law to criminalize undercover investigations and whistle-blower activity across multiple industries has led to additional scrutiny and criticism, including condemnation from groups such as AARP.

That has been a concern since before the law was passed, and it was part of the reason why the state’s governor opposed it. “While I support the purpose of this bill, I believe it does not adequately protect or give clear guidance to honest employees who uncover criminal activity,” Gov. Pat McCrory, a Republican, wrote when he vetoed the bill last May.

The state legislature quickly overrode his veto. Lawmakers who supported the bill have argued that it adequately protects whistle-blowers. Rep. John Szoka, the original bill’s primary sponsor, did not respond to a request for comment.

Just days after the law went into effect, Danny Miranda, a former poultry worker, was convicted on three counts of misdemeanor animal abuse following an undercover video Los Angeles–based Mercy for Animals released in December.

“We realized that the investigation could very well be the last undercover footage that was obtained before the ag-gag law taking effect on Jan. 1,” Vandhana Bala, MFA’s general counsel, said in an interview on Wednesday. She wouldn’t say if the release of the video was timed to highlight or critique the new law, but the connection has certainly been made in the coverage of both the video and Miranda’s conviction.

In addition to its latest undercover video, the group has conducted five other investigations in North Carolina, including one in 2011 that MFA believes led to the first-ever conviction for felony animal cruelty to stem from the abuse of commercial poultry. “Mercy for Animals does comply with all federal and state laws when we conduct our undercover investigations,” Bala said. As such, MFA, along with other animal rights groups, will not be conducting investigations in North Carolina until the legal climate changes.

For whistle-blowers, however, who often go out on a limb without the support and funding of a nonprofit to fall back on, even the specter of an ag-gag law can be chilling, according to GAP’s Hitt.

“These bills, these proposals, they win as soon as they step into a state and propose a bill,” she said. “The people who are the most vulnerable are silenced.” She added that plant workers, unlike the USDA inspectors critical of a slaughterhouse protocol trial that GAP supported in 2015, do not enjoy whistle-blower rights.

Nearly half of states have seen some sort of ag-gag legislation proposed, and laws have passed in six states.

Hitt said that North Carolina is different. “North Carolina is not just another state” with an ag-gag law to fight, she said. “We’re seeing it as a focal point of national attention. We want everyone in the United States to stand up and see what’s happening and to cry foul.”