What would happen when all the bots approve each other? The net cost is the fees and they have created a transitive trust island. As with the WOT issue (my limited understanding is) where someone currently follows a bot, their follower graph transitively trust the bot too.

If I follow you, any social engineering for a human to approve (maliciously or stoopidly) validate one of these linked bots would then orange check them all. Am I missing something?

(Certainly multiple attestations would help. Also weighting in a pagerank/eigenvector way would help)