function linkAccountWithFacebook()
 {
     //TODO should only work if logged in, but what should it return if not?
     if (!Facebook::signup_code_created()) {
         Facebook::redirect_to_login_prompt('/signup/linkAccountWithFacebook');
     }
     if (Facebook::csrf_checks_passed()) {
         $access_token = Facebook::get_access_token('/signup/linkAccountWithFacebook');
         $user = Facebook::get_users_info($access_token);
         $member = Member::currentUser();
         $member->addFacebookCredentials($access_token, $user->id);
         return Director::redirectBack();
     }
 }