Your Windows PC Has a Permanent ID That Follows You – Even With a VPN

Yes, it's bad, but worth pointing out, they didn't identify the user directly by somehow extracting GDID from their traffic, they identified them because their GDID happened to be in the same place at the same time at their hacking efforts that became statistically impossible to ignore.

Realistically this kind of tracking could be accomplished with any software with a unique ID that does, say, daily update checks or usage pings. This one is just extra bad because it's ubiquitous (on Windows) and almost impossible to change, so they have a 1-stop-shop for spying.