from Hacker News

Facebook recommends psychiatrist’s patients friend each other

by killwhitey on 8/29/16, 9:00 PM with 1 comments

• by elehack on 8/29/16, 10:55 PM

  Moral: don't use users' contact lists to bootstrap or enhance social services. Barring strong differential privacy implementations, it will cause problems.

  Implementing a 'what friends do I have on this service?' feature is one thing. Retaining that data and feeding it in to the recommender is very likely to cause this kind of problem.