[andrewinardeer]

I use this to find out who owns a mobile number.

Punch in the mobile number to the banking app and more often than not the mobile's owner name is displayed.

[cookie_monsta]

That's definitely a down side to it. I think you used to be able to choose your username, but now the only options my bank gives me are name + surname, first initial + surname or, oddly, middle name + surname

[ojr]

People do this type of lookup today with Cashapp