just looked at my iPhone 3GS and saw the purple location icon. i have location services turned off on almost everything so i got suspicious. went into the settings app and saw that under Location Services > System Services, "Traffic" was using my location. quickly turned it off, so now there's just the grey location icon next to it. only apps i had open were Phone, Messages, and Tweetbot. any idea why Traffic would be using my location randomly like that?