Less effective in what way? The actual answer is their use for training AI isn’t as good, but that’s not what I think you (or most other people) mean. The main use of them is to train AI via humans, the security is secondary and just a smart way to get free work.
Capchas aren’t generally case sensitive though.
Depends. I know that Microsoft changed to non-case sensitive not terribly long ago (for things like testexchangeconnectivity).
They’re not? Doesn’t that make them less effective?
Less effective in what way? The actual answer is their use for training AI isn’t as good, but that’s not what I think you (or most other people) mean. The main use of them is to train AI via humans, the security is secondary and just a smart way to get free work.
Less effective as the intended use of a CAPTCHA. Not as AI training.