Reddit still has Holocaust deniers, 9/11 truthers, misogynistic “men’s rights activists,” not to mention a community of nearly half a million people into gruesome videos of other people dying.

But all that material became a little bit harder to find Thursday. In what the social giant described as a “quarantine,” Reddit added content disclaimers to a number of controversial “subreddits,” including four with more than 100,000 subscribers each.

The quarantine affected the site’s main meeting places for Holocaust deniers, “men’s rights activists,” and sexless “incels,” as well as a number of subreddits related to white nationalism and the alt-right.

The quarantine also affected at least one subreddit on the left, R/FullCommunism, and a number of gory subreddits, including several devoted to video, pictures, or audio of people dying. A subreddit devoted to “IRL Streamer” Ice Poseidon, who streams his life online and is frequently pushed into bizarre or dangerous situation by his viewers, was also put behind the quarantine.

The quarantine doesn’t just make anyone wanting to visit the forums read a disclaimer. It also prevents the subreddits from coming up in searches, or appearing in summaries of the most popular material on Reddit.

The company also doesn’t earn money from the quarantined subreddits, according to a Reddit statement. In at least some cases, quarantined subreddits can only be viewed by users with registered accounts and valid emails—a huge setback for the subreddits, since Reddit users otherwise aren’t required to register accounts.

The disclaimers added to a number of the hate subreddits also include links to more moderate content. Visitors to R/TheRedPill, for example, a men’s rights subreddit, are now encouraged to visit a link to a site about “positive masculinity” instead.

The quarantine is the latest attempt by Reddit to stifle the spread of hate speech and misinformation on its platform. Earlier in September, Reddit deleted subreddits devoted to spreading the pro-Trump QAnon conspiracy theory.

Reddit has quarantined subreddits before, but a Reddit spokesperson told The Daily Beast that the Thursday quarantine marks an attempt to apply the site’s rules more consistently.

“Quarantine shields users from accidentally viewing content that may be offensive or upsetting by requiring them to explicitly opt-in,” the spokesperson said in a statement.

The move earned praise from some, with the Anti-Defamation League saying in a statement that it was “grateful” for Reddit’s decision to quarantine a Holocaust denial subreddit. But for others—including the leaders of some gruesome subreddits—the quarantines signifies a new crackdown at the site.

Russell Ryland, a moderator at R/WatchPeopleDie, called the quarantine a “slow death sentence” for his subreddit, which hosts shock videos of people dying in various ways. The verified email requirement alone, Ryland told The Daily Beast, would be a “huge hit” to the subreddit’s readership, which currently sits at more than 400,00 subscribers.

“Quarantine is obviously a way for Reddit to silence and kill subreddits that are not advertiser friendly,” Ryland wrote in an email. “Reddit is no longer the ‘bastion of free speech’ that they sold it to us as.”