Google started a identification service about 10 years ago or so. This identification service was meant to know 100% about people online.
When Google launched google plus, they wanted everyone to have real IDs and enter their entire life on their "social network" (some creepy ass shit).
As expected this creepy crap never took off. People went to Facebook instead, not knowing Facebook was just as creepy.
So, this identification service of theirs is meant to track you 100% online. They want to know exactly who you are. This includes spyware on Chrome browser, browser fingerprinting, webrtc, your screen resolution, IP history (not just your current ip), location and so on. By crossing all this data with machine learning, they are able to identify you anywhere with 90% certainty.
If you use Google on your phone then their precision is 100%.
This is why you get "I was banned by google and they ban all my new accounts" threads about 100 times a week. Google is tracking everyone, everywhere 24x7.