If you draft an email threatening someone and delete it without sending have you committed a felony because someone at Google could be reading your drafts box, stored in a datacenter across state lines?
FYI, the use of drafts folders to transmit messages has been used by terrorists. This is likely where CIA director David Petraeus got the idea when he needed a secure way to chat with his mistress.
https://www.findlaw.com/legalblogs/technologist/gen-petraeus...
This is a huge privacy problem that is only going to get worse.