How can I disable wp-login.php logo link?

Hi Folks,

I need to disable the wp-login.php logo link. I’m building a protected site that automatically redirects non-logged-in users to wp-login.php. As it stands, if a non-logged-in user clicks the logo on wp-login.php, it goes to the primary domain then automatically redirects to wp-login.php, essentially refreshing the page and losing any user/pass inputs that might have already been entered. This is particularly problematic on smart phones, where the logo is half the page and one errant thumb can cause the page to refresh and my users starting from scratch on incredibly tiny keyboards.

Any ideas?