private function __construct()
{
add_action('jetpack_activate_module_protect', array($this, 'on_activation'));
add_action('jetpack_deactivate_module_protect', array($this, 'on_deactivation'));
add_action('jetpack_modules_loaded', array($this, 'modules_loaded'));
add_action('login_init', array($this, 'check_use_math'));
add_filter('authenticate', array($this, 'check_preauth'), 10, 3);
add_action('wp_login', array($this, 'log_successful_login'), 10, 2);
add_action('wp_login_failed', array($this, 'log_failed_attempt'));
add_action('admin_init', array($this, 'maybe_update_headers'));
add_action('admin_init', array($this, 'maybe_display_security_warning'));
// This is a backup in case $pagenow fails for some reason
add_action('login_head', array($this, 'check_login_ability'));
// Runs a script every day to clean up expired transients so they don't
// clog up our users' databases
require_once JETPACK__PLUGIN_DIR . '/modules/protect/transient-cleanup.php';
}