Lockr

Abstract

Sharing personal content online is surprisingly hard despite the recent emergence of a huge number of content sharing systems and sites. These systems suffer from several drawbacks: they each have a different way of providing access control which cannot be used with other systems; moving to a new system is a lengthy process and requires registration and invitation of all one's friends to the new system; and the rules for access control are complicated and become more so as our networks of online friends grow.