No offending to Apple fans.
Type "File:///" (without the quotes), though comments there indicate that other combinations of upper and lowercase characters, perhaps typed quickly, can also crash applications under Mac OS X Mountain Lion - seemingly any applications, including the Crash Reporter.
quoted from： http://openradar.appspot.com/13128709
and http://www.theinquirer.net/inquirer/news/2241267/crash-almost-any-app-on-mac-os-x-mountain-lion-with-just-eight-characters
