On: MapTCHA, the open-source CAPTCHA that improves OpenStreetMap [video]

[glaucon]

Positive about the general idea, I hope it works out.

> Also, my first image had no bounding box at all.

Me too.

> "Swipe right if the red shape is correctly outlining a building. If not swipe left"

Rather confusing on a laptop which was showing "Correct" and "Incorrect" buttons.