Physicians and patients increasingly use social media technologies, such as Facebook, Twitter, and weblogs (blogs), both professionally and personally. Amidst recent reports of physician misbehavior online, as well as concerns about social media's potential negative effect on trust in the medical profession, several national-level physician organizations have created professional guidelines on social media use by physicians. Missing from these guidelines is adequate attention to conflict of interest. Some guidelines do not explicitly mention conflict of interest; others recommend only disclosure. Recommending disclosure fails to appreciate the unique features of social media that make adequate disclosure difficult to accomplish. Moreover, in emphasizing disclosure alone, current guidelines are inconsistent with medicine's general trend toward management or elimination, not just disclosure, of potential conflicts. Because social media sites typically rely on physicians' voluntary compliance with professional norms, physicians necessarily play a major role in shaping these norms' content and scope. To achieve the benefits of social media and ensure the veracity of social media content while preserving trust in the profession, physicians must reaffirm their commitment to disclose potential conflicts; advocate for better electronic disclosure mechanisms; and develop concrete management strategies-including, where necessary, the elimination of conflicts altogether.