Does Google know where we're going to go tonight?

[Amit]

They might have the capability; that is if you are logged into Google and leave a digital trail behind as to what your plans for the night are. Like e.g. planning for the evening over gmail, getting invites on gmail, making a plan on Google+ etc, or getting a eTicket for a flight on gmail, or self advertising your position to Google via a smart phone from which they can then discern some patterns etc. It is possible when you leave behind some clues on the Google controlled properties.

They might, but would they? I do not know.

And NO, it is not required of them to track your location, not even by government. What is required is that they retain some details about you like your activity stream/mail, your IP address etc; and yes the government can ask for the information. But the government cannot mandate that they spy at you, i.e. track your whereabouts. Well most governments cannot mandate that.