Patients have been criticised for taking photos and videos of doctors and then asking people online to rate how attractive they find them.
Social media posts of doctors are being shared without their consent, the British Medical Association's annual meeting heard.
Such posts "violate" their privacy, the meeting in Brighton was told.
Delegates voted in favour of a motion condemning patients for sharing private appointment recordings online.
Dr Zoe Greaves, a trainee GP who proposed the motion, said in most cases patients who posted photos and videos of their doctors without consent were doing so for baby scans or a child's first GP appointment.
But some posts were "far more insidious", she said, like those rating doctors on their attractiveness, as well as recordings of "terrible" GP appointments.
Dr Greaves said that friends who are doctors had found themselves the subject of posts on Twitter asking people to judge their looks.
"And for each of these, private consultations are opened up to public comment and critique, and the individual's privacy is undermined," she said.
Patients are allowed to record consultations for medical purposes to help them remember or understand what was discussed.
Dr Greaves said this could be a "valuable aide memoir" but she added that "there must be recognised responsibilities alongside that right".
Dr John Chisholm, chairman of the BMA's medical ethics committee, told the meeting that doctors could take legal action to seek to prevent or remove publication.
But he said in practice this would be difficult to pursue in UK courts.
The meeting's delegates, in passing the motion, called on the BMA "to lobby for sanctions against patients who breach their doctor's privacy".
A BMA spokeswoman said patients should seek the consent of doctors before making a recording.
"Should a patient publish audio or video recordings without consent, they may be at risk of unlawfully misusing the doctor's private information.
"Greater support and legal protection should therefore be afforded to doctors given the significant difficulties that they may face in trying to prevent publication or remove published material."