> As I browse, my interests are accumulated into basic interest groups, demographic data, and maybe recently visited websites that use tracking.
You are forgetting installing cookies and fingerprinting ( amongst others ) to track across platforms. You are forgetting using that data to target customers with tailored fearmongering news articles to better clickbait.
> Through that, Republican campaigns also access my grandmother's account, with all of her photos, likes, and comments. They use that data to learn her deepest fears.
I hate to break this to you but everyone does this. Obama did this. The democrats did. Hillary's campaign did this.
I love how you excuse news websites when they cause hysteria and panic over nonsense like campus rape crisis and pay gap in male and female sports. Not to mention the hysteria over cambridge analytica. Seems like the news has done far more harm to you than facebook did to your grandmother, assuming your story is legit and not made up.
I recommend you go watch the 13th on netflix to see how news and media can be dangerous. The problem now is that news has access to tons of data about us ( just like facebook ). The biggest difference is that facebook was pretty much "neutral" whereas the news/media are highly biased. Facebook allowed both trump and hillary political ads.