Many sign up forms will ask you for an email address so that they can contact you. Even the most minimal sign-up (other than no sign up) will need an email address to send you a validation email. ...
Many sites/services seem to make use of a security question as a way of accessing an account if you lose your password or email access. As an example, Facebook uses this form: There isn't a ...
When a user has entered incorrect details into a login form, is it better to tell them: The username or password you have entered is invalid. or The user name you have entered is invalid (for ...