I'm not saying I disagree with you here, because what you said is entirely correct, however there have been various instances in the past of social network comp

I'm not saying I disagree with you here, because what you said is entirely correct, however there have been various instances in the past of social network companies tracking people with the usage of cookies (those "share on X" buttons every website has) even outside their own domain. And on top of that, you have companies like Facebook doing data analysis on your personal aggregate data and then feeding it to advertisement companies even without your direct consent (although it is implied, either by the user's ignorance or negligence). This is obviously true for other companies as well, Google, Twitter, LinkedIn, etc etc. Obviously, the main problem here is not the company, it's the people using the company and the peer pressure on everybody else to join in. But that's another story.