Yep, Dennis already mentioned the cooldown, so they do have that. Of course some players will find ways to exploit it - there have always been exploitable things in pretty much any game (except maybe the original ‘Settlers’).

Happily, the new system brings a new element to the Purge and will certainly increase some dangers to bothe PvP and PvE servers, official and private (at least on Private there’s minimal exploits, etc)