In a recent episode of President Curtis, the President struggles with opening a door on two separate occasions.
These doors don't work because there are obstructions in the way: a body initially, then roughly a billion dollars worth of gold.
³Well, maybe "well-defined" is optimistic. After Bill Gates famously failed to download Movie Maker, everybody agreed that it was presumably somebody's problem, just not necessarily theirs. Ideally we can get even this level of accountability without the customer being Bill Gates.