Damus, a decentralized social networking app powered by the Nostr protocol, was removed from China's App Store by Apple on February 2, 2023, just two days after launching, due to directives from the Chinese government.

The Cyberspace Administration of China (CAC), the country's top internet regulation body, requested Apple to remove it from the China App Store, citing illegal content. The CAC stated that Damus did not meet China's requirements for social networks to incorporate censorship tools and link user signups to real identities. This direct communication channel between the CAC and Apple led to the app's immediate removal following the takedown notice.

Damus is powered by the Nostr protocol, a decentralized social media protocol designed for censorship-resistant communication. Unlike traditional social media platforms such as X or Facebook, which are centralized and controlled by single entities, Nostr operates on a decentralized network of relays that can be run by anyone. This decentralization ensures that no single authority can censor or control the information flow, giving users full control over their data and communications.

In June 2023, Apple threatened to remove Damus from its App Store over its tipping feature, which allowed users to trade Bitcoin directly without using other apps. Although this dispute primarily arose from a conflict with Apple's payment guidelines, Damus ultimately removed the tipping feature, which it considers equivalent to having a censored version of the app, just to remain on the App Store.

We sat down with William Casarin, the developer and founder of Damus to discuss their challenges with app censorship. Casarin shared their experiences, detailing their engagement with Apple after being censored in China. He explained how the CAC swiftly ordered Apple to remove Damus from the Chinese App Store, affecting around 24,000 initial users. Casarin also discussed challenges with Apple's stringent policies, particularly regarding Bitcoin tipping features, emphasizing Damus’ commitment to providing a free speech platform despite these obstacles.

AC: Could you explain what happened when Damus was initially launched in the China and Hong Kong App Stores?

D: After launching Damus in China and Hong Kong on January 31, 2023, the app quickly went viral in the Hong Kong App Store, reaching the second most popular spot within a few days. During this time, the cybersecurity division in China sent an official notice through Apple, which was unusual. I assume they have some sort of direct integration with Apple to act quickly on such matters. They didn't want our app to spread any further, so we managed to get around 24,000 downloads from users in mainland China before it was pulled from the China App Store. The app was never removed from the Hong Kong App Store, only from the mainland. Despite not having any Bitcoin or overtly controversial features, the app was censored and cut off.

AC: Did Apple forward you the notice from the Cyberspace Administration of China (CAC) to take down the app?

D: Yes, exactly. It was an email from Apple stating that the cybersecurity division of China had instructed them to take our app down. There was no opportunity to appeal either; the notice basically stated that our app was deemed against the law in China, and we had to remove it from the App Store, without specifying any actual law or legal statute. We are really just providing a free speech platform, which seems to be the biggest problem for the Chinese government's restrictions.

AC: What about the initial 24,000 users in China who downloaded Damus before the ban?

D: Well, those who already had the app installed on their device could still use that old version. But the real power comes from the ability for them to interact with users on any of the other client apps, making it extremely difficult for the Chinese Communist Party to completely cut off access to the entire network.

In response to censorship, I implemented more countermeasures, with a key discovery being that individuals in mainland China with Hong Kong accounts could potentially continue using the app. This suggested that a Hong Kong account could serve as a simple firewall bypass. However, the CAC began to scrutinize the Nostr protocol more closely a month or two later, leading to a ban on the relay. As we were using basic tools like web sockets and servers, they could target the IP of the servers. An interesting aspect was the ability to switch out the relays, meaning users weren't tied to the Damus relay and could even set up a private social network.

To counter the censorship, the app code was modified. Initially, the app always used a hardcoded set of bootstrap relays, which were all banned, causing the app to fail to load. With the code update, if a user switched out their relay set, this new set would be used as the bootstrap relay, potentially enabling continued use of Damus within China, possibly with their own relays.

Users in Mainland China can, for instance, simply use a web client, which is quite hard to ban, and still be able to interact with the Damus users. That's the strength of building on decentralized protocols, and I've always been a strong advocate of protocols over platforms. So, I think it's probably a major nuisance for the CCP if we continue to make it increasingly difficult for them. However, it's a cat and mouse game as they can keep banning relays.

AC: Could you detail the direct censorship from Apple regarding the Bitcoin features added to your app and share your thoughts on Apple's rules about permissible app functionality?

D: We tried to add features related to Bitcoin and tipping, and they explicitly banned certain things. For example, I can't put a tip button on posts, so I had to remove that. In a way, I have a censored version of the app in the App Store, just so I can stay on the App Store, which is disappointing.
On June 13, 2023, we unexpectedly received a notice from Apple stating that our app would be removed from the App Store if we didn't remove the zap feature—considered "tipping" digital content—within two weeks. Despite our efforts to explain that the content was already present and users weren't paying for digital content, Apple wouldn't relent. We had to remove the zapping feature, completely restructuring the app within the given timeframe. Regarding Apple's guidelines, it's evident that they don't apply their rules consistently, leaving enough ambiguity for arbitrary enforcement.