YouTube says it will ban videos with content related to the sale or assembly of firearms or firearms accessories, a move that has gun rights organizations up in arms.

YouTube, which not only is the largest all-video website but the website with the third-most traffic in the world, said it would begin enforcing the new policy in April.

“While we’ve long prohibited the sale of firearms, we recently notified [content] creators of updates we will be making around content promoting the sale or manufacture of firearms and their accessories,” a YouTube spokesman said in a statement, The Hill reported.

The website said it will ban videos showing the assembly of, advertising direct sale of, or linking to the online sale of high-capacity magazines and certain types of accessories used to simulate automatic fire or to convert a firearm to automatic fire.

YouTube lists bump stocks, Gatling triggers, drop-in auto sears, and conversion kits as some—but not all—of the types of accessories it will ban in videos. It defines “high-capacity magazines” as “magazines or belts carrying more than 30 rounds.”

In October, YouTube banned videos that demonstrate how to use bump stocks after the massacre in Las Vegas, where a gunman using a bump stock fatally shot 58 at an outdoor country music concert from a nearby hotel.

The National Shooting Sports Foundation, a gun-industry lobbying group, said the new policy is “worrisome,” Bloomberg reported.

“We suspect it will be interpreted to block much more content than the stated goal of firearms and certain accessory sales,” the National Shooting Sports Foundation said. “We see the real potential for the blocking of educational content that serves instructional, skill-building, and even safety purposes.”

“Much like Facebook, YouTube now acts as a virtual public square. The exercise of what amounts to censorship, then, can legitimately be viewed as the stifling of commercial free speech,” the foundation said.

The policies are written so broadly that they give YouTube the ability to censor any content it doesn’t like, said Karl Kasarda, co-owner of InRange TV, a site with firearms-related videos on YouTube, The Wall Street Journal reported.

“Their policies are not very clear cut, and they are arbitrary,” Kasarda said. “You never know when you are going to get hit by them.”

Kasarda said it isn’t clear whether the new policy will prohibit videos showing how to properly load a magazine into a gun.

Since a 19-year-old with a rifle killed 17 in February at a school in Parkland, Florida, gun control activists have pressured tech companies to shut down channels like that of the National Rifle Association, a nonprofit gun rights organization.

Specifically, activists pressured Amazon to remove from its streaming service the NRA-TV channel, a free streaming service featuring firearms-related content.

As of the time this report was published, the NRA’s official channel was still on both YouTube and Amazon.

“YouTube is now in the business of political posturing and censorship,” the NRA Institute for Legislative Action said in a written statement in response to the site’s new policy, adding: