In the wake of a new anti-harassment policy, Reddit is banning a handful of its worst communities. "Our goal is to enable as many people as possible to have authentic conversations and share ideas and content on an open platform," a group administrator post reads. "We want as little involvement as possible in managing these interactions but will be involved when needed to protect privacy and free expression, and to prevent harassment."

The most prominent removal — or, as the admins say, the only subreddit with more than 5,000 subscribers — is r/fatpeoplehate, a forum devoted to posting (among other things) pictures of overweight people for ridicule. A follow-up comment lists the other four subreddits as r/hamplanethatred, r/transfags, r/neofag, and r/shitniggerssay; they've all indeed been shut down, all but one "for violating the Reddit rules to keep everyone safe." According to the admin, these last four ranged from 149 to 3071 subscribers, although in r/fatpeoplehate's case, "more than 5,000" is a bit of an understatement; the last Reddit metrics (and a Google cached page) put it at around 151,000 subscribers.

Reddit's policy, according to the admin, is based on specific instances of harassment rather than general offensiveness. "We will ban subreddits that allow their communities to use the subreddit as a platform to harass individuals when moderators don’t take action. We’re banning behavior, not ideas," reads the post. That means that some apparently more offensive subreddits have been left online. One of these is the intensely racist r/coontown, a fact several commenters brought up. "While we don't agree with the content of the subreddit, we don't have reports of it harassing individuals," an admin replied. Reached for comment, a Reddit spokesperson elaborated slightly. "All five [subreddits] had numerous complaints that they were harassing people both on and off Reddit," she said.

There are somewhere around 650,000 subreddits, so shutting down five may seem negligible. But it's the latest step in a long debate over how broad the massive site's content restrictions should be. Over the past several years, the generally anything-goes Reddit has slowly shifted these limits to exclude sexually suggestive pictures of minors, "creep shot" forums dedicated to surreptitiously capturing sexualized pictures of women, and a subreddit that was central to distributing leaked celebrity nudes last year. The site has had long-standing policies against spam, vote manipulation, and posting "personal information" like someone's address or employment information.

Deciding which subreddits engage in harassment is going to be a difficult problem, especially because it's hard to even agree on what constitutes harassment — and that assumes everyone involved is acting in good faith, which almost certainly won't be the case. Then again, the same applies to categories like "personal information," an issue that came to a head when Gawker posted an exposé of one of the site's most vicious trolls. In a statement to The Verge, the company says said the site is taking "a step-by-step approach" to the recent harassment changes. "The Internet is an evolving medium and presents a number of challenges​ at scale,​ and we're learning and hopefully ​improving our place in it."

Disclosure: Alexis Ohanian, a co-founder of Reddit and its current executive chairman, has hosted a video series for The Verge.

Correction: An earlier version of this article incorrectly referred to Reddit administrators as moderators.