Exposing the level of detail in the data accumulated.
This starts at "opened the messenger app at this location on this date&time" and goes to "visited this Facebook-unrelated website on these times". Having to provide all of this data exposes the detailed profile they're getting on people.
If you decide to browse the web without uBlock Origin or if you decide to use Android, you know what you're being exposed to.
Time to step out of the bubble of tech-savvy people and talk to everyday users. It's unrealistic to assume everybody understands technical consequences, and it's unreasonable to require everybody to do so. That's why there is regulation. This applies to all fields, including medicine, food, and IT.
2. No, it doesn't matter if you use Android (what does using Android have to do with Facebook?) or not, Facebook can and will collect info on you through other means: analytics, logins, sharing etc.
3. You have very little to no idea of how pervasive tracking is especially in the case of large social platforms that everyone integrates with.
This is just clearly and verifiably false for the vast majority of users who browse the internet.
Consider, for example, giving your genetic material to a company that researches genealogy. Mostly harmless fun. That company is later quietly purchased- along with its databases- by a medical supplier. Meanwhile, cancer research has found that people with a particular gene sequence are at elevated risk for lung cancer. A partnership between the medical supplier and a medical insurance company means you can be screened for that risk without your knowledge, and suddenly you're screwed.
Even for those who don't see facebook as a malicious entity, there's considerable evidence that they do not exercise due diligence in storing and securing this information- see, for example, the recent case of leaking an enormous quantity of plaintext passwords via log files.
Enormous risks to individuals exist because the current regulatory environment poses no penalty to private entities for gathering personal information, sitting on it indefinitely, and transferring it to other entities until some purpose is identified. These risks may seem very small, but I believe that is mostly a fault of our collective imagination.
Then maybe exposing some of the third party quizzes, VPN's, and privacy apps that have poured more into the data vats. Possibly exposing the third party sources they've bought data from - connecting other data you didn't knowingly provide.
Who knows what else. Maybe they're afraid that once the full picture comes out they simply won't have users.
I say this in jest but at the same time I'm concerned this might be true.
Remember how you could cross post between twitter and FB ages ago? That went away for a reason!