In my own case, when I and a woman I mistakenly thought was a friend fell out, causing me to inform her that I wanted nothing further to do with her, I thought nothing of it when the police turned up at my door. It was irrelevant as I had no intention of contacting her again. However, armed with her official sounding Harassment Warning Notice she now spreads malicious lies around several societies of which we are both members, to the extent that I am unable to attend meetings without an escort for fear of further accusations.
This cannot have been the aim of the act.
I believe this woman may have used her influence as a magistrate to obtain her notice at the outset. Whether that is the case or not, the Protection From Harassment Act 1997 is a poor piece of legislation which has to be repealed or, at the very least, heavily amended. In its present form it is nothing more than a psychopath's charter.