Anger and confusion is brewing in the gun world amid an effort by YouTube to choke off inflammatory and explicit content. The move by the company appears to have broadened the criteria for what qualifies as a “restricted” video — and is therefore both invisible to viewers who’ve set their players to screen out offensive material, and ineligible to carry advertising.

YouTubers who post videos devoted to guns are finding that their channels have been affected by the change, cutting them off from some other fans and limiting the money that hosts can make from the ads that run with their clips.

The Firearms Blog, which maintains a YouTube channel with nearly 300,000 subscribers, was among the outlets to notice that ads were no longer accompanying its videos. Thanks to the removal of any revenue that creators use to cover costs and even make a living, YouTube gun channels are in danger of disappearing forever,” a posting read after employees noticed the channel’s own videos were no longer bringing in advertising dollars. Similar complaints swirled among gun enthusiasts on Reddit.

YouTube has also removed at least some gun channels from its advertising partnership program, which pays popular content creators according to number of pageviews.

On Friday evening, the Firearms Blog posted a video weighing in on the situation.

According to Google, YouTube uses “many signals—such as video title, description, metadata, Community Guidelines reviews, and age-restrictions—to identify and filter out potentially mature content.” Once YouTube has deemed a video inappropriate for users who select the platform’s Restricted Mode, that video cannot be monetized by its poster.

It’s not clear exactly when YouTube expanded its criteria for videos it considers “restricted,” nor whether gun channels were purposely included in the revised standards. YouTube did not respond to multiple requests for comment.

The creators of gun-focused YouTube channels are not the only ones upset by the expanded criteria. In late March, the video platform drew the ire of advocacy groups after some videos focusing on LGBT issues were censored. YouTube issued a statement saying it “was looking into” the concerns.

The giant video platform has come under increasing pressure from corporate marketers after a March 17 Times of London investigation found that videos uploaded by violent jihadists were accompanied by promotional spots from mainstream clients like the BBC and the British government. The jihadists who put the videos on the site would have received payments from those ads based on the number of page views counted by Google’s Adsense program.

YouTube also drew scrutiny in February after the Swedish videogame enthusiast PewDiePie, one of the website’s most popular (and well remunerated) personalities, was found to have used racist language and imagery in some clips. After PewDiePie was condemned for his use of offensive language, YouTube Red, a paid-subscription service, canceled its partnership with him.

The gun channels protesting the new policy are run mostly by product reviewers and amateur tinkerers who largely eschew common pro-gun political rhetoric in favor of geeking out over gear that is legal in most of America. They include personalities like Hickock45, a grandfatherly gun reviewer from Tennessee, and Taofledermaus, who makes and tests quirky custom shotgun shells.

Normally, the channel pages for such hosts are full of dozens of thumbnails of their many gun-filled videos. This Friday afternoon, when those same channels were viewed with Restricted Mode turned on, the pages appeared as almost completely blank.

Here’s what Hickock45’s videos page looks like with Restricted Mode turned off:

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And here’s the same page with Restricted Mode enabled:

Screen Shot 2017-04-07 at 7.25.44 PM

Several videos from the National Rifle Association’s official Youtube channel were similarly hidden from view.

“I think it’s just a panicked reaction from YouTube, to show advertisers they’re doing something after some recent bad press,” said Jeff Heeszel, the 50-year-old Californian behind the Taofledermaus channel, which boasts more than 800,000 subscribers. “I’ve read a lot of these angry posts on the Firearms Blog and elsewhere, but do we know that other channels outside the gun world aren’t also being restricted?”

Other gun YouTubers worry that the change has permanently crimped their livelihoods.

“Obviously YouTube has its own agenda as far as whether they support gun stuff or not,” said a host who goes by Royal Nonesuch. “Maybe their advertisers don’t want to be displayed on gun videos. But a lot of the channels affected are not objectionable. It’s reviews and stuff.”

Nonesuch, a 21-year-old from central Missouri whose real name is Richard (he declined to give his last name), is known to his YouTube fans for creating makeshift guns out of hardware store materials like pipes. He said that in 2016 he typically made $2,500 a month from ads hosted on his YouTube videos, and as much as $4,000 in a good month. The money was enough to quit his day job in retail.

But about six months ago, Richard said, he noticed his YouTube income started tapering off. In March, it cratered. One video he posted, showing how to fashion a homemade booby trap with a shotgun shell, garnered nearly 1.7 million views — but, he said, generated no Adsense revenue.

Heeszel noticed that his ad revenue similarly tumble in late March.

“My earnings were really low from March 25th through the 30th,” he said. “I was really panicking!”

Richard said he expects to make just $750 from YouTube this month. He is looking for jobs again.