Oh interesting! Ive done something similar but not didnt put as much effort.

For me, I just made an unending webpage that would create a link to another page...that would say bullshit. Then it would have another link with more bullshit....etc...etc...And it gets slower as time goes on.

Also made a fail2ban banning IPs that reached a certain number of links down. It worked really well, traffic is down 95% and it does not affect any real human users. Its great :)

I have a robots.txt that should tell them not to look at the sites. But if they dont want to read it, I dont want to be nice.