This paper explores the interplay between public policy in areas related to digital privacy and security and the development of new metaverse technologies that need to be compliant-by-design. Such interdependency is illustrated here through the proposal of a solution to implement seamless cross-metaverses avatar interoperability that preserves data privacy and portability. The new proposed scheme is based on the Self-Sovereign Identity concept and architectures, along with off-line governance agreements, in order to ensure that avatars can travel between metaverses while keeping whatever attributes they possess and that are compatible in the crossed metaverses. Many new and exciting avenues for technological research arise from such an interdisciplinary perspective.