1. A method comprising: accessing, at a client device, an object model representation of a structured document displayed in a browser client of a user to identify one or more elements of the structured document; and modifying, at the client device, the object model representation of the structured document to add one or more first controls proximal to respective ones of the one or more identified elements, wherein the one or more added first controls are operative, when executed, to transmit a message including an identifier of the respective element and an identifier associated with the user to a social networking system.