I'm one person who posts from several different computers - "home" on one side of the Pond, "office" ditto, "home" on the oither side of the Pond, using a different e-mail address in each case. If the system is set up to allow me only to use one address, which is what George Dubya seems to be suggesting, this will be a major inconvenience. I'm sure others must also use different addresses - perhaps when using laptop as opposed to desk PC.

Despite the different locations, I use the same username all the time.