If you type "fun facts" into the Google.com search box, you get a random piece of information using a wide variety of sources.

CNN: Google creates another time-waster with 'fun facts'

Because Monty's choice was not random (he didn't open just any box, he revealed a goat) the remaining probability of two-thirds gets squeezed, as it were, into the third box.

ECONOMIST: Getting the goat