Thousands of forums on the popular online message board Reddit are “going dark” for 46 hours starting Monday to protest controversial new fees levied at third-party developers.

Some of Reddit’s largest communities will be set to private for two days, meaning they will not be publicly accessible. By temporarily shutting off access to popular forums, “Redditers aim to pressure company executives to reverse their decision to charge developers for access to the site, which until now has been free,” NPR explained. In a post on Reddit about the boycott, organizers said that the new fees are  “a step toward killing other ways of customizing Reddit.” Over two dozen subreddits with at least 10 million subscribers and thousands of smaller networks are participating in the protest. 

Reddit users were outraged by the platform’s plan to start charging millions of dollars in fees for some third-party apps to continue having access to the site’s application programming interface (API). Mobile users sometimes use apps like Apollo, Reddit is Fun, and ReddPlanet to browse the platform’s forums. The pushback from the Reddit communities mirrors similar sentiments from Twitter users after the company similarly started charging for access to its API.   

Some of the more popular apps have announced they would be shutting down because the new fees, set to begin next month, were too expensive. “Reddit’s recent decisions and actions have unfortunately made it impossible for Apollo to continue,” Apollo developer Christian Selig tweeted last week. 

On Friday, Reddit CEO Steve Huffman hosted an open Q&A with users Friday in an attempt to address the outrage over the fees. “Reddit needs to be a self-sustaining business, and to do that, we can no longer subsidize commercial entities that require large-scale data use,” Huffman wrote.