I don't think anybody disagrees that Trade Me's board rules have been tweaked..

They said so themselves.
Within the new protocol is the specific 'don't abuse or harass people,' additionally that the boards are not a place 'for you to attack a person or their character.' The tweaks set out privacy issues for board members, just in case some board users are stalkers, like the sisters, who think they have propriety rights over other board members, their families and friends as well. Not a bad point really, but obviously a situation that preceded the 'tweaking' of the rules.
So the question remains, were those that Trade Me allowed to break the law before TM 'tweaked' the rules acting illegally, and if so why didn't TM take action earlier?
Those are issues that remain that TM will obviously be required to remedy.