public function findDuplicateUsernames() {
        $query = "SELECT 
u.user_id, u.username, u.user_regdate, u.user_regdate_nice, u.user_email, u.user_lastvisit, 
(SELECT COUNT(p.post_id) AS num_posts FROM nuke_bbposts AS p WHERE p.poster_id = u.user_id) AS num_posts,
(SELECT MAX(pt.post_time) AS post_time FROM nuke_bbposts AS pt WHERE pt.poster_id = u.user_id) AS last_post_time