This article by a pediatrician makes many valid points about the misuse of social media, something we all know too well, unfortunately.
Physicians are not allowed to address any public comments, acknowledge that they know any patient, and especially cannot fight back with negative comments of their own. Hospitals and medical practices can start addressing this by clearly posting information about the process involved for patients who have a complaint. They also need to monitor social media outlets and take these interactions offline as soon as possible. It will take time to see where all of this leads but a collective effort will be necessary to help the medical community respond appropriately.