With the question, I mean to ask if there is a possibility to prevent a Player from having more than 1 Account (to log in with), on the same Device.
I thought this through and like this, preventing someone from hacking, is a lot better.
Let´s say someone hacks with his created Account, my Game or App.
His/Her Account could be banned but then he/she would just need to create a new one, with any random inputs (E-Mail, Password, Username etc.), and that person would still be able to hack the App/Game.
But if there was a detection to check, if someone on a Device tries to register with more than 1 Account, on that one Device, hacking would be basically nearly impossible at this point.
Actually it would make hacking impossible, because normally you ban the Account of the Player (either through code (scripting) or manually on the PlayFab developer page) and if the Player/User of the App/Game would not be able to create any second Account or more, it would be a big step for Developers to protect their Game.
If this is not a feature yet, maybe it could become one?