As the judge said "[it] would be almost impossible without such technology". So it doesn't have to do with "on a computer", but companies like Facebook violatin

As the judge said "[it] would be almost impossible without such technology". So it doesn't have to do with "on a computer", but companies like Facebook violating privacy in ways that would have been impractical without computers, so it hasn't been an issue before. Imagine entering an electronics store in a mall and looking at a fridge. You leave the store, but an employee of the store had spotted you and what you looked at. They follow you out the door and into another store. There they whisper to an employee of that store "psst, give me $5 and I'll tell you what this guy's after". The other store's employee then proceeds to offer you a discount on a fridge. If some store had been doing that in meatspace people would have been up in arms, but for some reason because it's a "re-targeting ad" on a computer people have mostly been blind to what's going on. Facial recognition is the same. If you were doing it on the scale Facebook is doing it but in meatspace it would be illegal.