In the past, it was very difficult to work out what your privacy settings actually were and would change, often without users being aware. This has improved but it is still very difficult to work out some of the settings. For example, to delete you Facebook account can be problematic because even if you do find where to do it, should you inadvertently connect to Facebook again from some device, it negates your deletion.
Source article: Wired- Facebook Privacy Issues
Another article on the same subject: What the F*** Was Facebook Thinking and yet another one one how to delete your Facebook at https://vpnandgo.com/delete-facebook-account/
False information is about 70 percent more likely to be retweeted than faithful reports of actual events, researchers find.
False news—which the study defines as either inaccurate information presented as truth or opinion presented as fact—is on average about 70 percent more likely to be retweeted than information that faithfully reports actual events, the researchers found.
Source: Scientific American
In an article on Wired, they cover the steps required to be undertaken for the various services.