Firefox implemented something a few years ago where buttons on pop-ups were greyed out for a few seconds, to avoid this. I believe it was a security concern tha

Firefox implemented something a few years ago where buttons on pop-ups were greyed out for a few seconds, to avoid this. I believe it was a security concern that an online game could get you to click in a certain place at a certain time, and make a pop-up just before it asking for permission to do something, so you clicked Accept without meaning to.