I haven't used my Facebook account in years, ever since they recommended I connected with a person I'd known for 20+ years but with whom I shared no connections or commonalities apart from our nationality. As I remember it, neither of us had listed schools, jobs or interests in our profiles. Maybe it was a coincidence but it made me very anxious so I left the platform.
Maybe it was a coincidence but it made me very anxious so I left the platform. What were you anxious about happening as a result?
-- Yonatan Zunger, former chief architect, Google+
https://plus.google.com/+YonatanZunger/posts/WegYVNkZQqq
There are further historical lines of reasoning. Hacker News and its editors don't care to see them discussed: