Marketing doesn't need AI to effectively model our purchasing habits, to the degree that large percentages of the population are making purchases of things, "they didn't know they needed," solely based on the high amounts of "anonymized" data already out there.

I think we've already matched the level of intrusion that OP fears, there's no reason for businesses to purchase Gemini AIs (Copywrited, Reserved etc.)

For something like political persuasion, it's here, any of us have the tools available to make a convincing enough deep fake of a celebrity or politician. Don't trust anything you can't interact with, & don't trust those interactions as much as you personally know someone. With regard to news, find multiple trustworthy organizations, compare & contrast what that group of orgs has to say. Ideally, find some reliable sources with viewpoints differing from your own (I mean like WSJ vs. NYT, not some talking twits of social media).