More than 6,000 Reddit communities have gone dark and are restricting access to protest the changes to the company's developer billing structure, beginning Monday morning.
The blackout comes after Reddit told developers that it would begin to charge thousands of dollars for access to an application programming interface, or API.
"Don't Let Reddit Kill 3rd Party Apps!" a post announcing the blackout said. The organizers encouraged users to write complaints and boycott the platform. They also enumerated a list of demands, with resolving the API issues as top priority.
Among the concerns for the blackout organizers is allowing third-party apps to run advertising for the third-party developer's benefit.
Reddit, which has reportedly been mulling an IPO for years, draws the lion's share of its revenue from advertising. But the company has barred third-party apps from running their own ads or benefiting from Reddit's advertising platform, and that, coupled with the proposed API pricing, poses a significant risk to third-party developers, the blackout organizers have said.
Reddit is majority-owned by Advance Publications, the parent company of Condé Nast and a major shareholder in Charter Communications and Warner Bros. Discovery.
The popular third-party Reddit app Apollo would have been one of the hardest-hit by Reddit's billing change, which came after Twitter owner Elon Musk instituted comparable practices at the social media network.
Developers use APIs to communicate directly with a website's software or infrastructure, and they allow Reddit's third-party developer ecosystem to build applications and services for users.
Christian Selig, Apollo's developer, said the change would cost him $20 million annually, forcing him to sunset Apollo by the end of June, the developer said in a Reddit post.
The moderators of more than 6,600 subreddits — specialized communities that operate on Reddit — have taken their communities into private or restricted access as of Monday morning, according to a Twitch stream tracking the blackout. Communities dedicated to humor, gaming and gadgets are among those participating in the blackout, denying access to hundreds of millions of "Redditors" in protest.