Posted on Jan 04, 2024Read on

Blocklists: Decentralized Solutions to Combat Low-Effort Spam

Thanks to the Yup team, Dan Romero, and others for their feedback on this.

In the realm of online communication and social media, the proliferation of low-effort spam has emerged as a pernicious challenge, undermining the quality of discourse and user experience. Platforms like Farcaster and others are grappling with this issue, often with limited success. However, a notable solution has been presented by Bluesky – the implementation of blocklists. These are akin to Twitter lists, but rather than curating content to follow, they focus on filtering unwanted content by allowing users to block it. This approach, especially when built on a decentralized framework, offers a promising avenue to combat spam effectively.

Understanding the Blocklist Mechanism

Blocklists function as a barrier against spam by enabling users to collectively identify and exclude undesirable content or accounts. This collaborative approach leverages the collective intelligence of the platform's community, turning each user into a sentinel against low-quality content. Users can subscribe to blocklists curated by others, thereby benefiting from the vigilance and discernment of users or groups they trust.

The Decentralized Advantage

While this system doesn't need to be decentralized and may only consist of a few approved and permissioned listmakers, in a decentralized system, there is no single point of control or failure. This architecture enhances resilience against coordinated spam attacks and ensures that the blocklists are not subject to the biases or limitations of a central authority. Decentralization also aligns with the ethos of user empowerment and community-driven content moderation, key tenets of a free and open internet.

Bluesky's Moderation Lists

Bluesky, a decentralized social networking effort, exemplifies the implementation of blocklists in a decentralized context. It aims to transform social media into a shared public commons, where communities own and govern themselves. By focusing on community-driven moderation, Bluesky provides a scalable and user-driven mechanism to deter spam. This not only discourages scaled spam but also enhances the overall user experience by maintaining content quality and relevance. During its private beta, Bluesky actively responded to user feedback, shaping its moderation tools to reduce harm and protect users, while respecting the diverse views within the network​​.

Moderation in a Public Commons

In this post, we share why we believe a public commons is important for social media, as well as some proposals for moderation and safety tooling.

Call to Action for Other Platforms

Given the effectiveness observed in Bluesky's model, there is a compelling case for other platforms to adopt similar strategies. The use of blocklists on Farcaster, XMTP, and Lens could be a game-changer in the fight against low-effort spam, offering a more democratic and resilient approach to content moderation. This model shifts some of the burdens of content curation from the platform to the community, aligning with the principles of decentralization and collective intelligence.

Implementing Blocklists

For platforms considering this approach, a few key steps are essential:

  • Framework Development: Develop a decentralized framework that supports the creation, sharing, and subscription of blocklists.

  • Community/App Engagement: Encourage community and client participation in curating and maintaining blocklists.

  • Transparency and Oversight: Ensure transparency in the blocklist creation and subscription process, along with mechanisms for oversight to prevent abuse.

  • User Empowerment: Empower users with the tools and knowledge to effectively utilize blocklists.

Potential Challenges and Solutions

While the adoption of decentralized blocklists is promising, it is not without challenges. These include ensuring fairness in content blocking, preventing the misuse of blocklists for censorship, and preventing the manipulation or circumvention of blocklists. To address these concerns, platforms must establish clear guidelines and oversight mechanisms, while also fostering a culture of responsible and ethical content moderation within their communities.


In conclusion, decentralized blocklists present a novel and effective solution to the problem of low-effort spam on social media platforms. By leveraging the collective intelligence and participation of the user community, these blocklists can significantly enhance the quality of content and user experience. The success of Bluesky in this regard serves as a compelling model for other platforms to emulate. As we navigate the challenges of content moderation in an increasingly digital world, decentralized solutions like blocklists offer a path forward that is both democratic and resilient.