They're really concerned about the amount of information these big data stores have on them.
They're worried even more that there is a government snoop checking in on them or another unknown.
Personally, I have gotten more and more leery of putting data online. I deleted my Facebook 7 years ago. Twitter is strictly read-only for me. I share kid pics directly with family via private storage I control.
Really needs to be a peer-2-peer suite of "social" tools that cut out middlemen as much as possible.
Had she not been using it I would have written it off as confusing UI and "what's the point."
I avoid Facebook for many reasons. You have to be careful about who your posts are seen by. It's public by default. I have colleagues, family, and people I've met just once or twice on there. Any posts I make need to be inoffensive and anodyne. Scrolling down a Facebook feed fills me with FOMO, jealousy, rage, or other negative emotions. It's obvious they don't actually want to improve the core product. I feel used.