While the jury is still out on whether Meta’s new Threads will be a Twitter killer, the app could still upend how we think of social networks. Not because of how many users it has, but because of Meta’s promise to integrate ActivityPub, the decentralized protocol that powers Mastodon and other fediverse apps, into Threads.

Though that functionality hasn’t been built yet, there are hints about it sprinkled throughout the service. For now, the most prominent clue is the “threads.net” URL at the top of each user’s profile. It currently links to a brief message that hints at what’s coming. “Soon, you’ll be able to follow and interact with people on other fediverse platforms, like Mastodon,” it reads.

For close watchers of the fediverse — the collection of decentralized services that run on ActivityPub — those 15 words could be the start of one of the most consequential moments for the technology. While interest in the fediverse has been growing over the last year, it’s still not widely understood, even by some who are active on places like Mastodon. But Meta’s entry into the space could expose a lot more people to the power, and perils, of decentralized social networks.

What even is decentralized social media?

For enthusiasts, the rise of decentralized platforms represents an opportunity for a more open web — a chance to tear down some of the walled gardens that have become the norm on mainstream social media platforms. “It reminds me of the early, heady days of the Internet, when the web was happening,” Mike McCue, a former Netscape executive and current CEO of Flipboard said. “I believe that this is where the entire social media space will go.”

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Because they are open source and not controlled by a single entity, ActivityPub and other protocols allow users to interact with each other’s content, regardless of where it originated. The concept is often compared to email, which also relies on foundational protocols that most people don’t think much about.

“I can email somebody with a random .com address from my .edu address and it just works, the servers talk to each other and the email is delivered,” explains Ross Schulman, the Electronic Frontier Foundation’s decentralization fellow. Decentralized social media promises a similar experience, he says. “Instead of exchanging little short messages that we call emails, they exchange little short messages that we call social media, or images or likes, or replies.”

Right now, this kind of experience is limited to Mastodon and other, more niche services that make up the current fediverse. That’s not starting to change as larger and more mainstream platforms begin to experiment with ActivityPub.

Tumblr has said it plans to support ActivityPub. Blogging platform Medium started its own Mastodon instance last year, and now offers membership as a premium “perk” to paying subscribers. Mozilla has also started its own Mastodon instance, calling it a “long-term investment” in the future of social media. The BBC recently announced the start of a six-month experiment with Mastodon. News aggregator Flipboard is even more invested. The company has started its own Mastodon instance, promised to adopt ActivityPub and added integrations with Bluesky, another decentralized platform that uses its own protocol.

Why now?

Despite the recent surge in interest, the idea of the fediverse and decentralized, protocol-based social media is far from new. The ActivityPub protocol was officially established in 2018, but the idea of federated platforms is even older.

“ActivityPub is another instantiation of the basic idea of the internet … every node should be able to talk with any other node at the simplest level,” says Sorin Matei, communications professor and associate dean at Purdue University.

Though Mastodon gained some notoriety in 2017, much of the fediverse remained relatively obscure — until Elon Musk announced his plan to take over Twitter. The acquisition represented a “tectonic shift” for decentralized social media, Matei tells Engadget. New users began to flood Mastodon in the days immediately after his bid was announced, and there have been regular surges that coincide with controversial decisions he’s made since. The service currently has just over 2 million active users, according to founder Eugen Rochko.

Bluesky, another decentralized platform, has also notched early success. The service, which began as an offshoot of Twitter but severed all ties with the company last year, has racked up hundreds of thousands of users in its closed beta. Unlike Mastodon, the team behind Bluesky is developing its own federated protocol, the AT Protocol. For now, the only instance of Bluesky is the closed beta, but the company has said it plans to start testing federation.

And while the AT Protocol and ActivityPub are separate standards, the visions behind them are similar. Already, there are projects to “bridge” the two, and some fediverse enthusiasts suspect the distinction between the two will matter less as both Mastodon and Bluesky mature. “The most important thing is the first principles built around both these protocols are identical,” McCue told Engadget. “The most important thing is there’s an open protocol — actually two — to build the federated social web.”

For now, the number of people using the federated social web, though, is still small compared with more established platforms. Yet smaller and mid-size companies are investing in the protocols and the platforms they power because they see the surging interest as an opportunity to bolster their own communities. “They think it will actually create a better experience for their users,” Schulman told Engadget. “Whether that’s the promise of an even larger reader pool or access to more people to follow.”

Meta, which already operates some of the most dominant social networks, may have different motivations. While Zuckerberg has championed “interoperability” in the past, Meta hasn’t historically been welcoming to potential competing networks. Yet the company has talked glowingly about the promise of the fediverse. “Our vision is that people using compatible apps will be able to follow and interact with people on Threads without having a Threads account, and vice versa, ushering in a new era of diverse and interconnected networks,” the company wrote in a blog post announcing Threads.

Schulman notes that Meta may have more self-serving motivations. “They’re trying to portray themselves as not anti-competitive,” Schulman said, pointing to recent regulatory scrutiny.

It’s still unclear how long it will take Meta to actually add ActivitySupport for Threads. Instagram’s top exec has cautioned it will take time. In addition to technical complications involved, there are also serious moderation issues associated with the fediverse, where communities are responsible for setting their own rules and norms. Researchers have recently flagged the prevalence of CSAM on some servers. Bluesky, which does currently have centralized moderation, has also dealt with some controversies surrounding its handling of trust and safety. Meta will need to ensure that Threads, which has the same content policies as Instagram, is interoperable with the fediverse while keeping out content that doesn’t align with its rules.

The stricter approach may also explain why some fediverse backers were not excited about the prospect of Meta joining their ranks, even tangentially. Some Mastodon servers have pledged to block Threads in order to wall off their users from the Facebook owner. Mastodon’s Rochko alluded to the discontent in a blog post after Threads’ launch, assuring users that Meta won’t be able to serve ads or access the data of Mastodon users. But he made clear he was broadly supportive of Meta’s efforts.

“We have been advocating for interoperability between platforms for years,” he wrote shortly. “The biggest hurdle to users switching platforms when those platforms become exploitative is the lock-in of the social graph, the fact that switching platforms means abandoning everyone you know and who knows you. The fact that large platforms are adopting ActivityPub is not only validation of the movement towards decentralized social media, but a path forward for people locked into these platforms to switch to better providers. Which in turn, puts pressure on such platforms to provide better, less exploitative services. This is a clear victory for our cause, hopefully one of many to come.”