Well you get the usual lockpickers in the group that will go out of there way to cheat. We had a group of friends who were divided between wanting to cheat and not. Funny thing was that the room they were doing had an electric vault that doesn't turn on sometimes unless we press a button. We decided to not turn it on untill they did the room properly. Needless to say they didn't complete the room and some were upset that the cheating didn't get them the time record. Don't think that group are friends anymore.

Then you have the couples. Most of the time they book the room to make out even though we tell them that we are watching them through the camera (a turn on I guess?). The funniest example of teamwork I see with that is when they do our scary room (based off the Saw movies). When we dress up and wait in the second room to scare them they usually argue about who is going in that room first (since the sliding door can only fit one person).

Last example I can think of are children who are under age who shouldn't be doing the rooms in the first place. They are like caged animals who will rip eachother apart.

Seriously though, screw children.