This is really bad.
The Wall Street Journal's testing found that apps seemingly unrelated to Facebook were sharing user data with Facebook, including the location and price of home listings you view, and even sensitive medical information like body weight, menstrual cycles, and pregnancy status.
And they do this whether or not you are a Facebook user.
This is not a problem that can be addressed through consumer choice. The US needs something like Europe's GDPR.
arktos.social is a private Mastodon instance. Contact the administrator to request an account.