I was given this to find other people using the same IP
Does not seem to do the trick all the time but it catches a few
SELECT t2.USER_DISPLAY_NAME
FROM ubbt_USERS AS t2, ubbt_POSTS
AS t1
WHERE t1.USER_ID = t2.USER_ID
AND t1.POST_POSTER_IP
LIKE '55.23.219.444'
edited to say I can not figure out how to post the command and have it show