It's really no problem to do this. We're using a variation on this: https://unix.stackexchange.com/questions/158400/etc-shadow-how-to-generate-6-s-encrypted-pa

It's really no problem to do this. We're using a variation on this: https://unix.stackexchange.com/questions/158400/etc-shadow-how-to-generate-6-s-encrypted-password https://unix.stackexchange.com/questions/158400/etc-shadow-h.... The output of crypt (where the input is an email address) is pretty useless if we did suffer a data breach. They'd have to hash every known email address with that salt in order to figure out who had declined an invite from us.