The duty to preserve evidence, which arises when a party reasonably anticipates litigation, extends to all types of data sources that contain potentially responsive information. Attorneys routinely advise their clients to preserve data on computers, e-mail accounts, servers, and corporate databases. However, information on social media sites such as Facebook, Twitter, LinkedIn, Google+, MySpace, and others increasingly is being sought and used as evidence in litigation. Accordingly, parties to litigation are confronted with the issue of when and how they must preserve data stored on online networking sites.