> Despite what people often write and believe here, the access controls on PII data at Google are incredibly strict. You can't just arbitrarily train on people's personal data.

And yet Google is the largest online advertiser in the world. And yet, GMail used to (I don't know if it still does) push ads into people's inboxes.

I have as much belief in their PII controls as in their "Don't be evil" motto.