Definitely possible. Steam had something similar a while back caused by caching issues [1]. I have no idea about Facebook specifically though. [1] https://www.

Definitely possible. Steam had something similar a while back caused by caching issues [1]. I have no idea about Facebook specifically though. [1] https://www.forbes.com/sites/insertcoin/2015/12/25/steam-is-randomly-logging-users-into-other-peoples-accounts-and-exposing-their-information/?sh=7efffa1e301d https://www.forbes.com/sites/insertcoin/2015/12/25/steam-is-...