People are afraid of Facebook and Google. The level of knowledge they have about their users is immense and the world is worried about what is going to happen to that knowledge and how it will be controlled. For example, it is now possible to accurately predict a person's IQ just by looking at their Facebook Likes. (I know IQ is flawed, but predicting it is still both impressive and useful.) Not just that, but all kinds of other things about us that we don't necessarily think should be obvious can be teased out of such data such as our political affiliation, whether or not our parents divorced, whether or not we use drugs, and our incomes.
Obviously we have a reason to be worried about this data being used in ways we don't approve of. I would tend to agree with the majority that this is unfortunate but what people don't seem to get is how prevalent this sort of thing was already. It isn't exactly hard to figure out what profession a person is, how much money they have, what their sexual orientation is, and other factors after only moments of communication face to face. I should know since I did that for a living years ago. An incredible amount of data that we have no control over pours out of us at every one of our meetings - Facebook likes offer a new data stream but the idea that before this no one could figure these things out is ridiculous.
People can tell an incredible amount about you with only tiny amounts of information. Your name, the way you write, where you live, and who your references are are hugely important on a resume even though they cannot make use of facial tics, clothing, or appearance to give up information you want hidden. We stumble through life blithely unaware of how much people can determine about us without our consent or knowledge; the only difference now is that we aren't used to that information stream coming from a website. There is an implicit acceptance that the brand of your watch says volumes about you as a person but a fear that hitting Like on a brand of watch could somehow be a problem.
Sure it might be nice if all that could be eliminated, if somehow we could interface with one another in a sterile vacuum free of any information aside from that which we put in deliberately. That isn't going to happen though, not least because people don't *want* to live in such a place. You can have your sterile passing of information and I will take the messy, ugly, poorly understood real world. Shared glances, knowing smiles, waggling hips, and raised eyebrows are part of my world and I want to keep them. The same goes for trash talking people on Facebook posts and having awesome free email.
The information we reveal to the world digitally can be scary but when compared to what we are already used to revealing it isn't anything special. This is a case of fearing the Devil you don't know rather than sound risk assessment, I think. That doesn't mean we shouldn't push for good privacy controls on platforms such as Facebook and Google; we should, but we need to get over how dangerous companies knowing things about us is. They don't know more than a talented salesman who talked to you for 10 minutes and you hopefully aren't terrified of *that*.