I was travelling on the Northern Line earlier today, propped up near the door, reading a book. Anyway, an American gentleman politely pointed out that I was stood infront of the 'open door' button. 'Oh don't worry,' I reassured him, 'The door opens anyway - the button is a totally functionless placebo, designed to give you the illusion of agency.' 'Ah yes', he quipped, we've got something similar back in my home state. It's called a voting machine.'
Of course, when I left the carriage, I pressed the button nonetheless.