The police are grossly abusing their authority by continuing to keep registers of prostitutes, despite the fact that prostitution has been legalised. This is harassment, pure and simple. Now that prostitution is legal, they have no more reason to keep lists of prostitutes than of dairy owners. Unfortunately, it seems that some in the police just don't understand that, or are unwilling to accept that the law has changed. They need to be forcibly reminded that in this country it is Parliament that makes the laws, not the police.
Update (12 August 2022): And 18 years later, Blogger thinks this post - expressing a political opinion about the overpolicing of a legal activity - "violated our Illegal activities policy" (prostitution is legal in Aotearoa. As is freedom of expression). Fortunately the waybackmachine has a copy anyway.