Physicians are increasingly counted among Face-book’s 1 billion users and Twitter’s 500 million members. Beyond these social media platforms, other innovative social media tools are being used in medical practice, including for online consultation, in the conduct of clinical research, and in medical school curricula. Social media content is brief, characterized as “many-to-many” communication, and able to spread rapidly across the Internet beyond a person’s control. These and other features of social media create new dimensions to traditional ethical issues, particularly around maintaining appropriate boundaries between physicians and patients.