Passphrases like correcthorsebatterystaple are harder for hackers to crack than Tr0ub4dor&3s? Dropbox has implemented this on their sign-up form. The site objects if you try to register correct horsebattery staple as your password on Dropbox, the site (quite rightly) objects to the phrase. Very droll, says the web developer at Dropbox who implemented this for the likes of tr0ub and Tr”]
Source: https://nakedsecurity.sophos.com/2012/08/13/correcthorsebatterystaple-dropbox-wit/