Brute Force

https://hackerone.com/reports/127844

https://www.arneswinnen.net/2016/05/instabrute-two-ways-to-brute-force-instagram-account-credentials/

https://www.arneswinnen.net/2016/03/how-i-could-compromise-4-locked-instagram-accounts/

https://hackerone.com/reports/125505

https://hackerone.com/reports/144616

http://www.anandpraka.sh/2016/03/how-i-could-have-hacked-your-facebook.html