Low value bots (spam bot) can be suppressed by bandwidth limiting and usually removing their financial incentive is enough.

I was considering doing something to break the trails, it's easy to detect account that blindly follow some authors, and the fact that it happen with users at high level is concerning, (Ex. @timsaid trailing @gavvet). I don't see it as being so much of a problem though as vote count doesn't affect the user experience. (unfair reward does though)

What would also be great is to have a way to reduce reputation of an account that isn't posting anything. Whatever that would do, it would be in a way disagreeing with someone's voting pattern.