Techniques for substituting references to content shared within the social networking system. In an embodiment, a first reference to a first version of content is received. A second version of the content is selected based on at least one optimization objective. A second reference to the second version of the content is created for provision to a user of a social networking system. The second reference is provided for the user. The at least one optimization objective includes at least one of a business objective, a technical objective, and a legal objective. The content may include at least one of video and audio.