Web 2.0 users have many choices of content-hosting or application-service providers (CSPs). It can be difficult for a user to share content with a set of real-life friends and associates; intended viewers of the content may have different CSP memberships than the content sharer. Web 2.0 users need usable mechanisms for sharing their content with each other in a controlled manner across boundaries of CSPs. In this position paper, we discuss the problem users face and propose a solution that builds upon the existing secret-link mechanism. Our proposed solution does not require users to setup another account on each CSP to view shared content and does not require any special software being installed. The mechanisms for content hosting and sharing are separated; CSPs do not need to change their existing access-control mechanisms.