userid change in the url after completing registration

/community/registration/completed/1?userid=1000 change the userid to 1200 or what ever and you will see that user e-mail address , is this going to be fixed , have it hashed or encrypted at least so it can't be looked up that easy. or simply tell me where I can change it so it just says "activation code has been sent to your e-mail address" instead showing the actual e-mail