I want to disable login at all on my drupal site, even better also hide the form. If i need login i will enable it from a ssh session and after working disable again.
I will prefer to do this with rewrite rules in .htaccess but i cannot figure out the right rule.
Update (as this seems to be a popular question)
I ended up with .htaccess like this:
# disable well known Drupal user login endpoints
RewriteCond %{QUERY_STRING} q=user
RewriteRule ^/?$ http://%{HTTP_HOST}/? [R=307,L]
RewriteRule ^user$ http://%{HTTP_HOST}/ [R=307,L]
RewriteRule ^user/register$ http://%{HTTP_HOST}/ [R=307,L]
# goto user login with that "secret" URL
RewriteRule ^op9__P87? /user [NC]