It's been said, but really, it should be opt-in rather than opt-out. If you really need this, just ask. If I'm feeling particularly nice that day, I might even allow it, but when I discover their mischief after they've done it, there's no way I'll be okay with it.

If there's one good thing, they remove the data they've collected from you if you opt-out. (But it'll be already fed to the machine learning system, I guess.)