In haste. I would suggest that the fundamental issue here is not Facebook or other social media "hidden truths", but freedom.
If I have this right (and please correct me if I am wrong), it seems that it is a fact of life that currently the only way to avoid the Facebook and Google tracking of our IP address transactions is to browse anonymously through a VPN (Virtual Private Network).
It is a characteristic of the way the Internet works that our browsers send out an http header to every site we visit. The header includes lots of data - e.g., our browser name and version, possibly our MAC or PC details and maybe even our email address (depending on how we have configured the browser), and of course the header has to be preceded by our IP address so that the server being accessed knows the address to use to send back a response.
I used to use the now obsolete JunkBuster which could spoof the header and spoof/deform the cookies, but it could not do anything about the IP address.
Big Brother (the State) wants to know, and makes sure that it does know (or can find out), where and who we are and what we are doing when we are online. It is all faithfully logged.
Nowhere has this been shown to be more true than in reports of communist and Fascist states' tracking or control of user activity (e.g., China, Iran), but democratic states (e.g., US, European, Australasian, Canadian) are categorically not excluded - in fact, the latter invented and perfected the tracking (Google even did it for the Chinese government, at one point). The IP address is our virtual and (usually) actual geographical location key. If you do not operate via a corporate and fixed IP address (where everything is logged by default), then even though our private ISP will dynamically reassign a different IP address if the ADSL router/modem disconnects/reconnects or is reset, that key is valid for all session activity from that point on up to the next point of disconnection, and is faithfully logged by our ISP. Newly-assigned keys are similarly logged by our ISP as soon as a session is started. Those logs are saved for an extended period, the length of the period depending on local statutory regulations, for the purposes of tracking for criminal activity - which includes, for example, child pornography and file-sharing copyright infringements in an increasing number of states/countries - and which can be scrutinised for those purposes under legally enforceable requests from relevant police/state authorities or state mafia. We are obliged to accept this - the difficulties of enacting/imposing these legal controls on users' Internet activity in the current Internet system can only be overcome by reducing our right to freedom/privacy whilst we browse, and sites consided by the State to be "illegal" may even be commandeered (taken over) or blocked from us by the State (e.g., China, Iran).
Even if you have a VPN, the provider of the VPN services will have logs of your activity also, and it is a matter of record that these logs can be and have been provided to relevant authorities (e.g., to the FBI) on their legally enforceable requests. Though Facebook and Google currently have no legal right to access these logs, that could change overnight by statutory mandate if they successfully lobbied state authorities and if the State thus decided that it made sense to delegate such monitoring to reduce the costs of direct State monitoring. Anything is possible here, which is why I used the word "currently" in the opening sentence of this post.
So, if you woke up this morning, feeling refreshed and secure in the almost certain knowledge that you live in a democratic, free State, where your rights to privacy and freedom of speech are securely maintained, then you are living in a warm and fuzzy state of illusion. Whilst you were sleeping, your freedoms and rights on all fronts will have already been even further eroded by remorseless State Fascism and corporate Fascism that - like rust - never sleep. It's all about money and power.
Some recent examples:
(a) The US police department of Renton legal action to secure the identity of the satirist who produced YouTube cartoons that Renton police only thought was aimed at them, and so wanted to retaliate and exact retribution/revenge. This is effectively a direct attack on US First Amendment rights. Google were being required to reveal the ID and IP address of the YouTube cartoon author.
(b) Different secular states (e.g., including US, Canada) considering enacting laws to make it an offence to criticise religion or upset the feelings of religious people (this after pressure only from Islamist organisations like the un-indicted 911 co-conspirator CAIR and the Muslim Brotherhood). Christians and other sects have been fair game for as long as they have been around, and that is exactly how it should be - e.g. the cases of the RC priesthood's well-publicised penchant and belated recompense for buggery of little boys could never have become so public or have been remedied otherwise.
(c) The UK government's responses to the recent chav riots - including the increased scrutiny and control of Blackberry device usage logs, and increased CCTV surveillance.
(d) The US government's tacit approval of Philip Morris International's (Big Tobacco) involvement in activity in Indonesia which is banned and would be illegal if carried out in the USA - e.g., targetting children and the young in general for tobacco advertising/sale. PMI bought out the state's biggest tobacco company some time back and now has a monopoly - even 2-year olds are encouraged to smoke (check YouTube for examples/TV documentaries), and even the Indonesian government health department sponsors mumbo-jumbo treatment for people, including children, where nicotine and smoking are prescribed remedies ("spiritual tobacco" use). This sort of thing will be putting at risk potentially millions of Indonesian citizens (including a large proportion of children), but it must be generating good corporate profits for the PMI US head office, and the stock (share) price will look good as a result - which is a main objective. And that has to be good for State tax revenue on all fronts.