A button that will only be visible to people who have had at least 5 cups of coffee that morning.
A button that will only be visible to people who have watched a minimum of 3 episodes of cat videos on YouTube.
A button that will only be visible to people who can recite the entirety of Pi to 50 decimal places.
A button that will only be visible to people who have successfully trained a snail to navigate a 3-foot hurdle.