Every once in a while when we have irreligious people over for shabbos or yom tov we get asked the question:
Are you allowed to flush the toilet on shabbos/holiday?
Well we usually crack up and go "duh, who'd keep shabbos if you couldn't?"
"Would anyoone use their own bathrooms if you couldn't? Don't you think everyone would head off to the shul or something?"
Well, I've got news, pretty soon that question will be legit, here's why:
Just What the Economy Needs: A $5,000 toilet