[kragen]

Maybe you could require hashcash, so that people who wanted to do automated searches could do it at an expense comparable to the expense of a human doing a search manually. Or a cryptocurrency micropayment, though tooling around that is currently poor.

[supriyo-biswas]

The only issue with a hash cash is there’s no way to know whether the user’s browser is the one who computed said proof of work, or has delegated it to a different system and is simply relaying its results. At scale, you’d end up with a large botnet that receives proof of work tokens to solve for the scraping network to use.

[kragen]

I don't see that as a problem; it still imposes the botnet rental cost on the spammer or whoever.