This is similar to hashcash proof of work concepts that inspired Bitcoin. Use proof of work to make not traffic expensive, to create a financial disincentive for running the bot.<p>I'm curious to see if Tor users get impacted by this.<p><a href="https://en.m.wikipedia.org/wiki/Hashcash" rel="nofollow">https://en.m.wikipedia.org/wiki/Hashcash</a>
Is there something better than a CPU intensive task? They obviously are worried about the power consumption.<p>I'm thinking a memory and time intensive task that is minimally CPU intensive would be better.