[caslon]

"We're using your personal conversations for training data. Thanks."

This is acceptable. Consumers click without reading, and don't have any strong organizational ability to punish Google for this.

"We're training our AI on the questions of your idiot employees who are inevitably going to submit user PII CSVs or PDFs or even just outright draft emails to suppliers with our tool. Thanks."

You don't want to pick this kind of fight with a corporation, and as a corporation, you don't want this to happen to you.

[ceejayoz]

Sure, in this case. But I can’t use my family Gmail account for my Nest thermostat for the same reason.