The practice that Google has been employing has potential dangers in that a particularly skilled individual could use multiple cell towers to triangulate someone's location to within or quarter-of-a-mile or closer.
'However, we never incorporated Cell ID into our network sync system, so that data was immediately discarded, and we updated it to no longer request Cell ID'. So, for example, if I'm on Verizon and in the USA, my Android phone would send this data back to Google. A Google spokesperson says the company's push notification system is "distinctly separate from Location Services, which provide a device's location to apps". Google pledged to put an end to the data collection by the end of the month, or at least not beam back home cell tower data, a service that Android users can not shut down. It is the latest example of the tech giant ignoring privacy of those on Android or those using Google products. The company had been "looking into" using the data to speed up message delivery.
This isn't the first time Google's run into issues where it's failed to clearly inform users on what kind of data it's collecting and how it's doing so, and it definitely won't be the last. Google said that it never stored or used the information though. Google wasn't spying on people, and a hacker wouldn't have found a treasure trove of data sitting on Google's servers.
You thought you were completely disconnected from any location tracking by Google and your phone when you went into your phone's location services and toggled them off, right? Google does offer details on how to control Google's location access points, though after reading through the instructions, the company could admittedly do a better job of making this clearer and simpler for its general consumers.
As for what's being collected, the data is not as accurate as it could be. The data collected is encrypted, but the information still likely contains a unique identifier that when paired with the location info collected, does pose some security risk. Even if the user actively turned off location services, Google can still access their location and movements without their knowledge. Even if there is no SIM card on a phone, it still uses WiFi to send the tower address.
It is unclear how identifying the nearest cell tower could be used to improve Google's message services.