Im beginning to think that, as annoying for users and difficult to build a userbase for as it may be, the answer might ultimately have to be for future social sites to charge people for use in some way, be it to create accounts or as a subscription or just for the ability to post/comment/vote or whatever. If it’s no longer going to be feasible to keep bots out, and there’s a financial gain for their use, then they’re going to get used, so at that point it has to be somehow more expensive to run a bot than that bot can be expected to bring in as a result of it’s contribution to an advertising or manipulation campaign, to deter them. On the bright side, I guess it might lead to a shift away from advertising everywhere. Either you charge people and therefore dont need ads, or you dont, and have most of your ads being “seen” by bots, which advertisers probably don’t want to spend money to reach anyway.