We do know what you are referring to with the ACS (AntiCamp System) setup, and how it can be cheated. The internal policy is that if a GM is present and sees somebody clearly abusing it like this, they issue a manual punishment. Therefore, if somebody is abusing it, and a GM is definitely present and deliberately ignoring it, report that GM.
ACS is a basic kill counter/timer system to prevent single-victim counting. The system could be expanded much further to keep track of multiple victims, so simply targeting one or two additonal people would not save you from the ACS. However this kind of change would take much time and testing to work right, and still work efficiently. So until then, my first paragraph is the way to go.