if i was implementing something like that it'd probably be with some kind of flash+localstorage cookie tied to a hardware ID, allowing you to reuse the same bro

if i was implementing something like that it'd probably be with some kind of flash+localstorage cookie tied to a hardware ID, allowing you to reuse the same browser/machine with 0.05 factor security, but if you cleared everything, you went through the entire normal login flow again, possibly asking for sms verification or email link clicking