Facebook's Friend Suggestion Feature Recommends Patients of Psychiatrist to Each Other

Facebook's 'People You May Know' recommendation algorithm began suggesting patients as friends to their psychiatrist Lisa, and recommending fellow patients to each other. Lisa, a psychiatrist who infrequently used Facebook, noticed that her patients - mostly senior citizens and people with serious health or developmental issues - were appearing in her friend recommendations despite not sharing contacts or having any obvious digital connections. One patient, a 30-something snowboarder, began seeing recommendations for elderly and disabled individuals he recognized as fellow patients from the psychiatrist's office. Another female patient received a friend recommendation for a fellow patient she had only seen in the office elevator, suddenly learning their full name and profile information. Lisa had not friended any patients or looked up their profiles, and there was no shared guest wifi network. The most likely explanation was that patients had Lisa's phone number in their contacts and had given Facebook access to their phone contacts, allowing the algorithm to infer connections between all parties. Lisa expressed serious concern about this 'massive privacy fail' given that her patients include people with HIV, suicide attempts, and women in violent relationships. The medical community began recommending patients not log into social media at medical offices or even leave phones in cars during appointments.