Methinks it's an OPK/telekil prevention... mechanism. What it does is that it makes the OPKer lock onto the mannequin and then proceed to shoot the heck out of the doll, causing no damage to anybody else.
Although, I think that the placement could have been better... most people will think that their computers are going nuts. (I don't see why Nexon didn't put them under the map, in a place where nobody else can reach.)