If I may, I don't think it is completely ludicrous that major amusement/theme parks may adopt the use of metal detectors of one sort or another. I know the local park (at least the last time I visited) had them being used. True, there is a difference between in the volume of guests coming through the gates, but I wouldn't say that it couldn't be done.
Of course having them would not be able to stop all acts of violence. However, they can serve to limit the number of these acts and the extend of the damage and injuries done.
All other Theme Park Employees post your stupid guest tricks here. This forum is not for general Theme Park discussion. Please use the Break Room, for non stupid guest trick topics.