1) users often use the same username and password on various websites, despite this being dumb (because it's so convenient) 2) if you ask such a stupid questio

1) users often use the same username and password on various websites, despite this being dumb (because it's so convenient) 2) if you ask such a stupid question you probably won't be able to properly secure the machine hosting this 3) your users will be totally screwed when you get hacked And this is why you should never store passwords but only a salted hash, and never trust any service that can email you your password when you click "I forgot my password".