A warning to would be iPhone and iPod Touch application developers was posted on Apple’s developer site yesterday: “If your app uses location-based information primarily to enable mobile advertisers to deliver targeted ads based on a user’s location, your app will be returned to you by the App Store Review Team for modification before it can be posted to the App Store.” The message is a bit concerning, and confusing, to many would be developers who planned on monetizing their application by selling location based advertisements. What does “primarily” mean? If Google Maps or Urban Spoon were to insert location based advertisements into their applications would that be allowed? After all location data is being used to supplement the main function of those applications, using it for advertisements would not require a separate call to Core Location. What if Tap Tap Revenge or Shazam were to use location data to display advertisements from local businesses, would that be allowed? You do not need any location data to play Tap Tap or use Shazam, and a separate call to Core Location would be needed. We like the idea of Apple protecting the use and abuse of Core Location data, but isn’t that why the iPhone prompts you every time a call to Core Location is made?