When sites collect phone numbers to "find friends", there is always a chance that they will be leaked. And even worse, someone having enough resources will chec

When sites collect phone numbers to "find friends", there is always a chance that they will be leaked. And even worse, someone having enough resources will check all existing phone numbers and get a mapping between numbers and accounts. This reminds me of a story posted on Russian site [1], where researchers managed to bypass Instagram's protection and find accounts by phone number. Sadly, I cannot confirm described method because their site requires a Google Account to find Instagram account by phone number. But if it's true it shows that even Facebook and thousands of its engineers cannot protect their users' data. [1] https://translate.google.com/translate?sl=ru&tl=en&u=https%3A%2F%2Fhabr.com%2Fru%2Fcompany%2Fpostuf%2Fblog%2F479094%2F https://translate.google.com/translate?sl=ru&tl=en&u=https%3...