Comment by jks

Quixotic[0] (my content obfuscator) includes a tarpit component, but for something like this, I think the main quixotic tool would be better - you run it against your content once, and it generates a pre-obfuscated version of it. It takes a lot less of your resources to serve than dynamically generating the tarpit links and content.

0 - https://marcusb.org/hacks/quixotic.html

How do you know their site is down? You probably just hit their tarpit. :)