8. A system comprising: one or more processors; and a memory coupled to the processors comprising instructions executable by the processors, the processors being operable when executing the instructions to: by a server, receiving an identification of one or more objects or references to the objects embedded in a structured document displayed on a client device to a first user, wherein: the structured document is a markup-language document displayed as a webpage; and the objects originate from one or more sources external to a social-networking system; by the server, access a social graph of the social-networking system to: determine if one or more second users having an association with the first user have accessed or are accessing any of the identified objects; and retrieve, from the social-networking system, one or more social-network data elements comprising social-network profile information provided by one or more of the second users to the social-networking system; and by the server, send to the client device one or more instructions to modify, for at least one of the objects, the structured document displayed as a webpage to the first user to indicate that the object embedded in the structured document and originating from the sources external to the social-networking system has been accessed or is being accessed by one or more of the second users, wherein modifying the structured document comprises displaying, proximal to the object, one or more of the social-network data elements.
11. The system of claim 8 , wherein the processors are further operable when executing the instructions to: responsive to one or more detected interactions by the first user with one or more of the objects or references in the structured document, receive data indicating one or more edge relationships from the one or more objects or references to the first user; and send the data indicating the edge relationships to the social-networking system.