The document discusses the evolution of identity cards from static "Information Cards" to dynamic "Relationship Cards" that give users more control over their personal data and digital identities. It introduces Higgins, an open-source identity management platform, and describes how Relationship Cards work by sending pointers to user data over front channels, while user-managed back channels allow bi-directional sharing through various protocols. Relationship Cards and personal data agents aim to put individuals in control of their online identities and preferences.