That could be possible, but humans who can answer the captcha's would still hold an advantage because the bots would have to scale their votes to keep the rShares below the amount needed to avoid a captcha.  At least with what I'm proposing but there could be other ways to further limit them.  I amn't proposing to limit them completely just looking for ways to help humans compete without having to resort to automation.

It would mostly be minnow bots who could vote and never come across a captcha, but they don't gain anything from curation anyway so there should be no incentive.