This "feature" came installed on my Toshiba Satellite from a year ago. It pretty well sucks, requiring you to have enough light, align your face properly, and turn your head left and right. Takes about 1-2 minutes. Takes me maybe 1-2 seconds to type my random 8 char password...

I'm fairly sure that the version of X-Com: Apocalypse on Steam is also using a third-party crack, just judging by the quality... It occasionally asks for the CD to be re-inserted, despite being run in a DosBox environment with mounted CD image. This of course makes it unplayable...

Nope, definitely ID10-T.

Ubuntu didn't change the key. On any kernel with the "magic SysRq key" enabled (which Ubuntu has), Alt+SysRq+K kills all running processes on the current VT. Therefore, it kills X.
Ubuntu's recent decision to disable Ctrl+Alt+Backspace by default is a separate issue.
On older versions of Ubuntu, you will find that either key combo will kill X.