Maybe I'm not being clear...
In the absence of clear, well-considered privacy laws (which I'm not the least bit hopeful for, particularly internationally consistent..), Google will have access to this data. As a randomly chosen user, there's probably nothing I can do about this (assumption being the average random user can't figure out how to enable e2e encryption). So Google will be data mining my data, if they choose to. And note I'm only choosing Google here because the user I replied to used Gmail as an example, I don't think Google is particularly unique or special in regards to using their user's data for profit.
Under those assumptions, if Google finds something illegal, they should say something, right?
There are a number of "outs" here. Privacy laws, Google giving me the ability to opt out/encrypt my data, ...
Do I want this? Hard no, but that's really not my point.