Nonfree (proprietary) software is very often malware (designed to mistreat the user). Nonfree software is controlled by its developers, which puts them in a position of power over the users; that is the basic injustice. The developers often exercise that power to the detriment of the users they ought to serve.
This document reports instances where proprietary software is tethered to a server.
Adobe applications require periodic connection to a server.
The iMessage app on iThings tells a server every phone number that the user types into it; the server records these numbers for at least 30 days.
A half-blind security critique of a tracking app: it found that blatant flaws allowed anyone to snoop on a user's personal data. The critique fails entirely to express concern that the app sends the personal data to a server, where the developer gets it all. This “service” is for suckers!
Google/Alphabet intentionally shut off home automatic control products that depend on a server to function. The lesson is, don't stand for that! Insist on self-contained computers that run free software!