Entire site requires login, needs ACL. Where to put authentication check?

[eluser]Zack K.[/eluser]
Extend CI_Controller by putting a file called MY_Controller.php in application/core/ and putting the following,

Code:

class MY_Controller extends CI_Controller {
function __construct() {
parent::__construct();
//TODO:Put logic here.
}

}

Then in your controllers you would extend MY_Controller instead of CI_Controller.