The movedTo property (a link) on an actor-type object indicating that the actor in question has "moved" to a new location. That is, the actor in question is no longer used and the movedTo link points to a new actor where the user's activities can be found. When displaying an actor with a movedTo property, clients should show a description of the linked-to actor as well, with some explanatory text ("This user has moved to ...").
This property is for advisory purposes only—the actors are still considered separate entities and nothing about this property should affect addressing, delivery, or lookup. Additionally this property should not be used by servers to take any sort of automatic actions, such as following the new user or unfollowing the old user.
note that if people have ideas about how to do automatic delivery things well or automatic following/unfollowing those would be good possible changes to this property, but right now we're not confident enough in figuring out the edge cases yet.