It didn't seem to matter what response I sent to PerplexityBot, the requests kept coming. I guess it's not surprising that a badly written bot isn't monitored either.
Can you use hashcash or some proof of work system somehow? I don't know anything about this space.
They were only requesting the HTML, not using a headless browser.
There was the tarpit that sends out markov-chain-generated random words, loading very slowly . If the client has a limited number of concurrent requests, that could theoretically choke the client.
> a badly written bot
I think that it's fair to say that these bots aren't badly written. Their behavior is entirely intentional.