Reminds me of that hunter2 password thing. http://www.bash.org/?244321 http://www.bash.org/?244321 Basically, the website doesn't know which of the squares are

Reminds me of that hunter2 password thing. http://www.bash.org/?244321 http://www.bash.org/?244321 Basically, the website doesn't know which of the squares are red, that depends on your browser state. By clicking the red squares, you're feeding it data. The interesting observation I made out of this is that navigating there in an incognito window prevents any links from being considered as visited. That's good to know.