yes

SELECT COUNT(*) as PMs, u.USER_DISPLAY_NAME as PM_Hog
FROM
ubbt_PRIVATE_MESSAGE_USERS pmu, ubbt_PRIVATE_MESSAGE_TOPICS pmt, ubbt_USERS u
WHERE pmu.TOPIC_ID=pmt.TOPIC_ID
AND pmu.USER_ID=u.USER_ID
GROUP BY pmu.USER_ID HAVING PMs>40
ORDER BY PMs DESC
that query, when used in your admin cpanel, database tools, sql command will show you who the PM hogs are too..
note "PMs>40" you can change that number 40 to something more meaningful to your forum PM limits

