Password Difficulty

Through the years I, myself, have been a big pusher of tough password regulations. Always making users have a symbol, number, and letter in their password. Recent changes in technology, including the power of computers, have made these password easier for computers to guess. Why then do we continue to use these difficult to remember passwords? We do this because of an antiquated idea that if they are tough for a human to remember, they should be tough for a computer to guess. XKCD has come out with a great response to the question, "why isn't your password more difficult?"

Source: XKCD