Keep calling the police. If they don't want to do anything I've found that telling them if they don't help you that saying something like "okay well me and my mates will 'sort him Jim out' ourselves" kicks them in to action.
I did something similar 2 years ago when I found the address of a guy who stole my bag. They didn't want to help until I implied I might confront him myself, possibly with a weapon.
Cool, but as with most of the anti-AI tricks its completely trivial to work around. So you might stop them for a week or two, but they'll add like 3 lines of code to detect this and it'll become useless.
Honestly to me this claim seems like a stretch. This artist is not the first person to do these kind of high contrast futuristic acid graphics either.
And then things like claiming the double chevrons, symbols in boxes and "aleph" (which is a marathon thing to begin with) next to some text are directly lifted from their designs when they are also common design elements as well, all just seems like someone trying to milk some fame out of this.
And also you famously can't copyright an artsyle.
Edit: after going through the thread and seeing higher quality images, I take all this back. The symbols in the boxes and the aleph text are litterally exactly the same, this is stealing.
The problem is consistency.