They might be able to, but they won't unless this is requested by police or law enforcement. Police or law enforcement aren't likely to request this unless a major crime is involved or suspected.
If you have a free Apple iCloud account, you didn't have Find My iPhone enabled with your iCloud account settings on the iPhone?
Message was edited by: Allan Sampson
The Find My iPhone app has nothing to do with this. The Find My iPhone app on your iPhone is used for someone else to locate their iOS device or Apple computer with your iPhone or for you to locate another iOS device you own with your iPhone.
With the Passcode Lock feature, nothing can be accessed on your iPhone which includes an option to completely erase the iPhone after 10 failed passcode attempts. This also prevents someone from turning Find My iPhone off with your iCloud account settings on the iPhone and the same for turning Location Services off which is required for Find My iPhone.
Since you didn't have the Passcode Lock feature enabled, you have changed your iCloud account password and the same for every other email account you were accessing on the iPhone, and you have reported this to your carrier and to the police?