This is one of the "problems" or feature you get with android, that it wants to sync a lot of things with the cloud (the internet), because this is just the way google thinks people should handle their data.
If you haven't switched it off manually in the settings, the hero does a lot of background sync, which will cost you extra money if you don't have some kind of flatrate for data with your provider. so i would either switch the use of background data off or just get a contract where (at least some) data use is included.