As in Iowa, ag-gag proponents in Missouri met resistance to an initial, far-reaching bill, including from the state press association. In retreating to a narrower measure, though, Missouri proponents hit on a novel idea. Rather than barring investigators from taking pictures or video at agricultural facilities, the law requires employee whistleblowers to submit any evidence of suspected animal abuse to the authorities within 24 hours.

This new gambit gave proponents an opening to claim the anti-abuse mantle for themselves—and to portray activist groups like Humane Society of the United States and People for the Ethical Treatment of Animals, which typically gather footage of mistreatment over a months-long period, as indifferent to animal suffering.

“If abuse does in fact occur, it needs to be dealt with immediately instead of being sensationalized months later as a fundraising tool for extremist animal rights groups like HSUS, PETA, and others,” said Lonny Duckworth of the Missouri Cattlemen’s Association, in praising Gov. Jay Nixon for signing the measure into law.

The law also, without directly targeting journalists, threatens to disrupt the way investigations are conducted. And it raises new questions, for journalists and their sources. For one thing, how can anyone—activist, journalist, or concerned employee—responsibly complete an investigation in a 24-hour window?

“Oftentimes, investigations by journalists can take days or weeks or months … building your case, vetting your information,” Horvit said. “… If you’re not given time to do that in a way that’s appropriate, the story can fall through, and that causes great harm to the journalistic process.”

Mike McGraw, a Kansas City Star reporter who has done important investigative work on abuses in the beef industry and lax USDA oversight, told me that the Missouri law “could backfire on industry” by not affording investigators the time to seek a response from management before running to the authorities.

Some opponents argue that requiring an investigator to surrender evidence to the state within such a short window of time is plainly unconstitutional.

“That’s why there’s a due process in this country,” said Mickey Osterreicher, general counsel for the National Press Photographers Association. “If you want something or need something, it needs to be subpoenaed.”

Neither Iowa nor Missouri has a media shield law protecting journalists from being compelled to give up sources or evidence, although court rulings in both states have afforded some limited protections.

Send in the drones

In addition to these battlegrounds, the ag-gag wars may now be spreading skyward as well.

This year, Missouri state Rep. Casey Guernsey, the architect of the state’s original ag-gag legislation, also put forward a bill to prohibit the use of unmanned surveillance aircraft, except for limited law enforcement purposes.

A host of anti-drone measures, promoted by civil libertarian groups, have popped up in states and municipalities across the country. But according to Scott Pham, director of the Missouri Drone Journalism Program, the anti-drone movement in the Show-Me State may not be motivated entirely by constitutional concerns.

“Here in Missouri, I think it’s very transparently connected to the ag-gag movement,” said Pham, who runs one of only two “drone journalism” programs in the nation along with his duties as content director at public radio station KBIA.

Citing language in Guernsey’s legislation that bars drone surveillance of “any individual, property owned by an individual, farm, or agricultural industry,” Pham says the real purpose was to protect agricultural operations from scrutiny—by regulatory agencies or journalists.

“I consider that an ag-gag bill,” Pham told me.

Guernsey was unconcerned that his bill might impede the work of journalists; if anything, he seemed to welcome the idea. “If I’m hearing about drones being used to gather information from a news standpoint, I would say that would be at the top of my list of concerns,” he told KCTV in Kansas City.

Pham told Guernsey that his drones were flying only over public lands and being used for environmental reporting, rather than investigations of private individuals or businesses. “We’re not out to do gotcha stories,” he told me.

Pham did acknowledge, however, the enormous potential for future journalists and activists to use drones and other aerial means to carry out the kinds of investigations that are becoming increasingly hard to conduct on terra firma.

If adopted, those strategies will inevitably provoke further legal controversy.

Last month, photojournalist George Steinmetz was arrested after taking aerial pictures for National Geographic while paragliding over a Kansas feedlot. Animal-rights activists seized upon the case as an ag-gag arrest, though authorities charged Steinmetz with trespassing for taking off on private property—a charge he denied.

The Steinmetz case may be a foreshadowing of the air wars to come, says the NPPA’s Osterreicher, who has written about the coming legal battles over drone technology.

Deron Lee is CJR's correspondent for Iowa, Missouri, Kansas, and Nebraska. A writer and copy editor who has spent seven years with the National Journal Group, he has also contributed to The Hotline and the Lawrence Journal-World. He lives in the Kansas City area. Follow him on Twitter at @deron_lee.