https://news.ycombinator.com/item?id=16474938 https://news.ycombinator.com/item?id=16474938 https://gizmodo.com/how-facebook-figures-out-everyone-youve-ever-met

https://news.ycombinator.com/item?id=16474938 https://news.ycombinator.com/item?id=16474938 https://gizmodo.com/how-facebook-figures-out-everyone-youve-ever-met-1819822691 https://gizmodo.com/how-facebook-figures-out-everyone-youve-... The fact that 90% of your friends upload contacts/emails is plenty of information about you.