Proving one isn't a bot is not so easy
In a time where bots are so common, and where they are increasingly "intelligent", it feels like more work to prove one is NOT a bot than it is worth. Numbers, images, passwords, linked codes, facial recognition... If there is one thing I have learned in watching technology over the years - "the more you tighten your grip, the more star systems will slip through your fingers." And most hackers and bots are much smaller than that.