If you've got a Jelly Bean device -- say a shiny new Nexus 4 -- and open up Google Now today, you'll likely be greeted with a notice about Google's location policy. The notice reminds users that Google does keep location history in order to serve location-relevant information (like traffic and walking stats), and prompts to be granted additional access to this data. This looks to be related to those "distance walked and ran" cards users saw a while back.
Even though you're reminded of this whenever signing into a new device or starting Google Now for the first time, we don't think it's a bad idea for Google to remind users of the data being collected.
More: Google Nexus 4 Forums