how can we stop this
 

when mouse over thread, the content inside show up itself, how can we stop it? or allow usergroup use that option only. please take a look of my picutre

edit vBulletin Options/ Forum Display Options/ Length of Thread Preview Text

You can use this hack to let users decide for themselves if they want this or not.
Found it quickly because I have this hack installed. Works great :)

thanks princeton, i didn't know we can disable them in acp, thanks again