I work for a school district and one of the hottest items for the kids to sneak onto our servers is a tool called Inviible Chat. I tried to google an answer as to how to block off this thing, since it poses a problem as far as the obvious implications of cheating and/or not paying attention in class. "Kids will be kids", I know, but the school guidelines prohibit chat/im programs and this one needs to be no exception to that rule. All of my google searches have only led me to download sites for this program and NOT to an answer as to how to stop its use. Any help would be appreciated.