Contemporary privacy challenges go beyond individual interests and result in collective harms. To address these challenges, this article argues for a collective interest in Mutual Privacy which is based on our shared genetic, social, and democratic interests as well as our common vulnerabilities against algorithmic grouping. On the basis of the shared interests and participatory action required for its cumulative protection, Mutual Privacy is then classified as an aggregate shared participatory public good which is protected through the group right to Mutual Privacy.