They don't have to. The possibility to opt out from tracking have been available for a while, although it was always pretty hidden in the settings. After I opt

They don't have to. The possibility to opt out from tracking have been available for a while, although it was always pretty hidden in the settings. After I opted out, I started seeing awful ads: mostly semi-naked bodies of people claiming to lose weight or bald heads. Of course it's easy for Google to just say that this is what their economically optimized algorythm selects for a perfect stranger, because those are the only advertisers that risk spending ad money on someone they know nothing about. Long story short: it's a sort of bribe already and you cannot prove it is happening.