Excludes any user that does not have the "edit_post" capability from using myCRED.

exclude-subscribers-from-mycred

/**
 * Exclude Subscribers
 * Excludes any user that does not have the "edit_posts" capability.
 * On a default WordPress installation this will exclude all users with the
 * "Subscriber" role.
 * For more information on roles and capabilities please consult the
 * WordPress codex: http://codex.wordpress.org/Roles_and_Capabilities
 * @version 1.0
 */
add_filter( 'mycred_exclude_user', 'exclude_subscriber_from_mycred', 10, 2 );
function exclude_subscriber_from_mycred( $reply, $user_id ) {

	if ( ! user_can( $user_id, 'edit_posts' ) )
		return true;

	return $reply;

}