Tumblr was never explicitly a space for porn, but, like most things on the internet, it is chock full of it anyway. Or at least it was. On Monday, to the shock of the millions of users who had used the microblogging site to consume and share porn GIFs, images, and videos, Tumblr banned the “adult content” that its CEO, David Karp, had defended five years prior. In the hours after the announcement, sex workers panicked, users threatened to leave, and—in classic Tumblr fashion—online petitions calling for change gained hundreds of thousands of signatures. But Tumblr’s porn ban isn’t about porn or Tumblr at all, really. It’s about the companies and institutions who wield influence over what does and doesn’t appear online.

When Melissa Drew, an adult content creator and model, logged in to Tumblr Monday afternoon, she was greeted by a deluge of unfamiliar posts and notifications. Her usual feed, perfectly curated after nearly a decade of tinkering, was awash with panicked posts from fellow adult models, memes about the policy change, and goodbye posts. Drew’s personal blog, which she had relied on as a public-facing way to tease the content available to her Patreon subscribers, was lit up with notifications from Tumblr informing her that most of her posts violated the new rules.

When Yahoo bought Tumblr for $1.1 billion in 2013, critics warned that premium advertisers wouldn't exactly be clamoring to run ads in a sea of porn. Yahoo CEO Marissa Mayer disagreed, arguing that targeting tools would keep content that isn't "brand-safe" (read: porn) away from ads. In an interview shortly after the acquisition, Karp doubled down on the platform’s openness to porn. “When you have … any number of very talented photographers posting tasteful photography,” said Karp, “I don't want to have to go in there to draw the line between this photo and the behind the scenes photo of Lady Gaga and like, her nip."

But the nip line has indeed been drawn, and it’s a doozy. Though Tumblr’s Monday announcement had technically only prohibited depictions of sex acts, “human genitalia,” and “female-presenting nipples,” a much wider swath of Drew’s feed was quickly caught up in the ban. “I had everything from nude, censored nudity, and lingerie photos flagged,” she told WIRED. “I still haven’t dealt with removing all of them yet—I just sort of heavy sighed and closed the tab.”

Safe Space

In interviews and messages with WIRED, more than 30 sex workers, porn consumers, and creators on Tumblr lamented the loss of what they described as a unique, safe space for curated sexually themed GIFs, photos, and videos. Many users who had used the microblogging site as their primary source for porn were at a loss when asked where they would go after Tumblr’s ban on “adult content” goes into effect on December 17. For the thousands of sex workers who used the site to share their own explicit content in a controlled, relatively contained manner—not to mention the countless others who used that content to fill the hyper-curated feeds of some of the site’s most popular porn blogs—the crackdown’s consequences are even more difficult to unpack. And researchers say the ban could shrink Tumblr’s user base, which already appears in turmoil over the decision.

The move comes less than two weeks after Apple pulled Tumblr from the iOS App Store after child pornography was found on the site. Though the offending illegal content was removed quickly, according to Tumblr, the app has yet to return to the App Store (it was never removed from the Google Play Store). In its most recent blog post, Tumblr stated that its longstanding no-tolerance policy against child pornography should not be conflated with the move to ban adult content. The latter, Tumblr argued, was inspired by a drive to create “a better Tumblr.” But these sorts of decisions aren’t made in a vacuum.