Accepting Facebook friend requests from current or former patients is a lousy idea, the British Medical Association is telling physicians. The group's new social media guidance notes that "because of the power imbalance that can exist in any doctor-patient relationship," it's important to establish a professional boundary. And that can be tough to do given all the personal information a Facebook status-update stream can deliver. You can imagine a scenario, for example, where a doctor sees pictures posted on Facebook of a patient he knows to be three months pregnant at a party, with a cigarette in one hand and a beer in the other. Is it ethical to bring it up at the next visit, even if she doesn't?