Apple clarified that the data is a small portion of their crowd-sourced location database cache of Wi-Fi hotspots and cell towers which is downloaded from Apple into the iPhone for making location services faster than with only GPS, therefore the data does not represent the locations of the iPhone. The volume of data retained was an error. Apple issued an update for iOS (version 4.3.3, or 4.2.8 for the CDMA iPhone 4) which reduced the size of the cache, stopped it being backed up to iTunes, and erased it entirely whenever location services were turned off.[239] The upload to Apple can also be selectively disabled from "System services", "Cell Network Search."