The simplicity of it is logic defying. It used to be that you had to find crosswalks or move puzzle pieces or type blurred letters and numbers, but NOW all the sudden I can just click a box and HEY!, I’m human?
That’s hardly the Turing Test I’d expected.
To clarify, websites can’t capture keyboard events that were typed into a different website like you’re thinking. Think of going to a web game that let’s you use WASD for controlling your character. It’s able to capture those events on that page because its in focus. When a site goes out of focus (such as switching tabs or switching to another window that’s not the browser), it loses that ability. Overall, it’s very secure.
I was more wondering how you thought capturing the mouse movements would lead to security issues.