Should I retire 'thesaunderschild' name on YouTube and forums?

For years now, the same Australian "WAnker" has been harassing me on (mostly unmoderated) forums, monitoring me on YouTube, and bugging me on wikis. This guy is my age too (37).

This obsessive behaviour includes calling me names endlessly, saying disturbing things about my mum having an aortic bulge, tagging me, or signing up with my alias to post crap on an anxiety site, because it was unregistered with me going by another nickname.

So I figured out the guy behind the abuse quite some time ago is this idiot that I knew from forums going from as far back as 2004, yet it never shook his confidence to abandon his demented antics, and he stupidly denies that he is even in Western Australia despite having proof.

I wanted to broadcast a game this week on YouTube on my "thesaunderschild" channel. However, he got my address and in the past, he came on my streams just being a moron. He subscribes to me, but he hides the channels he is following. Blocking someone also doesn't prevent them from knowing your activity.

I've attempted to change my ID on the forums I visit, but he obviously knows it's the same profiles anyway, so he just made a humongous list of the pseudonyms I was using, along with spamming my real name and address, and mentioning personal issues I had with people.

He is really disturbed. But I did call the cops in Perth last year. They claim if you live in the UK, they cannot arrest his ass, due to there being cracks in the system. Is that true, though?

He's a jackass.