--> Tracking Phones, Google Is a Dragnet for the Police <--
"When detectives in a Phoenix suburb arrested a warehouse worker in a murder investigation last December, they credited a new technique with breaking open the case after other leads went cold.
The police told the suspect, Jorge Molina, they had data tracking his phone to the site where a man was shot nine months earlier.
But after he spent nearly a week in jail, the case against Mr. Molina fell apart as investigators learned new information and released him. Last month, the police arrested another man: his mother’s ex-boyfriend, who had sometimes used Mr. Molina’s car."
I usually don't trust Google, but on this issue I tend to see email as paper mail — it's inherently not private, and the overload of private information that goes through it is a problem regardless of Google's presence in the exchange.
I find the usual alternative, attaching identity to mobile phone numbers/SMS, even worse. Other alternatives, like WhatsApp, are proprietary, restrictive, and also harvest data from users.
In the heyday of paper mail, you wouldn't get a copy of your entire grocery receipt back in the mail. There was a lot of sensitive information (e.g. a credit card bill) but it was less fine grained than the information that leaks from order confirmation emails.
Maybe that's something merchants should be careful about.
If something in your life runs afoul of Google, your identity gets shut down. This wouldn't be a big deal if you weren't using Gmail as the hub for tons of your identity and logons--but many people use it for exactly that.
TLDR; non-meta risk is high and unpredictable if you use Gmail as a life hub, much lower otherwise.