More on-the-record, official information from David Drummond (Google's chief legal officer): http://goo.gl/D6eEk
@SEOEnquirer you are certainly welcome not to believe me; I'm just a guy who has worked at Ft. Meade and at Google.
You can add location information to your Tweets, such as your city or precise location, from the web and via third-party applications. You always have the option to delete your Tweet location history. Learn more
@SEOEnquirer you are certainly welcome not to believe me; I'm just a guy who has worked at Ft. Meade and at Google.