Seeing an image of 2B disappointed by UN boat clicking simulator, I realized what would be useful is not another CAPTCHA, but a CAPTNHA, a test to tell apart niggers rather than computers, regardless of their hardware, so here is a first iteration approach to the concept, requiring user to be capable of at least some spatial reasoning: https://gitlab.eientei.org/eientei/captnha

Compatible with kocaptcha API, so it can be a drop-in replacement for pleroma.