Originally Posted by
RichardInSF
Google is a notorious information thief, they don't want to allow you to opt out of it. It's not just Google maps that knows, it's all of Google's products. As long as you use gmail to receive reservation confirmations, they'll know. Might consider another non-Google email address just for that purpose.
It pulls from gmail. Hotels, too.
Only way out is to either suppress email confirmations at booking or send them to another email address.