Here’s a quick rundown (based on my analysis of the help pages and this video) of what Google’s done to help give users control of their information flows in Latitude: * Only friends you have explicitly invited or accepted can see your location * You can hide your location to everyone so no friends can see where you are (and neither will Google) * You can hide your location to select friends * You can share only city-level data with select friends * You can manually select a location on the map that will be shared with friends (which means you can send the wrong location to obfuscate your location) * And, perhaps most importantly, Google is not logging your pings to servers; they only keep you latest location on file
http://michaelzimmer.org/2009/02/06/with-latitude-google-actually-got-it-mostly-right/