Number 1 is the only one that counts. 2 is something you agree to when you make an account. Don't like it, don't sign up or just don't post stuff. Number 3 is a basic business practice. They're a company, their aim is to be successful, and your data is the way they do that. Again, if you don't like it, don't make an account.
People don't understand the implications of losing control of their own information, especially to a company that does not intrinsically set out to protect their members.
I was once a member, but I killed my account after one of the awful changes to the T&C's. Unfortunately, they still have my data even though my account is "gone".