Remove them from your theme? A query wouldn't do much..
UPDATE `mybb_posts` SET `icon` = '0'
UPDATE `mybb_threads` SET `icon` = '0'
That will only delete the post icons from the database, not actually delete the columns and everything.
Thanks faviouz, !
SQL Query would be a better, just like Ratings
It would indeed, but to completely disable post icons you'll have to edit all of those templates. If you'd like a setting to be added in MyBB 2.0 share your opinion in this thread:
http://community.mybb.com/thread-98457.html