The problem of privacy can be usefully summed up with the line
perceived value of usefulness > perceived value of any immediate privacy / control concerns
Hence for example when we have events such as Snowden and revelations of secret laws then our general view starts to drift towards privacy / control concerns and we start to question whether the usefulness of services such as Google exceed this? Prior to Snowden then usefulness generally outstripped any privacy / control concerns for the majority.
The real problem of course here is marketing and perception. Whether we like it or not, marketing is very effective at promoting perceived value of usefulness and diminishing other concerns when it comes to selling stuff.
Post Snowden, marketing will continuously tip that balance in favour of selling more products 'tailored to us' and collecting more of our information. Our concerns will diminish, they're doing it for our benefits and our needs - aren't they?
The system which basically intrudes into highly personal details of our lives is promoted as creating values of safety, security, comfort i.e. 'Mother knows best' etc. You could do a mock up of the entire page with malicious hackers having taken control of your information which would make people run a mile. But marketing won't do this, it's not their job to provide a balanced view, it's their job to promote a specific view and even create user needs when none existed before.
The problem you're fighting with privacy is therefore Marketing, our own perceived desires (whether real or fabricated for us) and the desire of companies to sell products and gain more access to our lives. Snowden was a fortuitous event that exposed some of the excesses of what is happening but it will be forgotten and ultimately buried. There will be niches, people with longer term memories who are not easily swayed by the bright lights of marketing - but they're niches.
If you want to fight the erosion of privacy and create an environment where users are under more control in a more egalitarian society then you either need to create commercial interests in line with this or robust legislation. You need to be willing to use marketing to diminish the perceived value of usefulness and raise the perceived value of privacy / control concerns.
This means getting dirty.
You'd have to oversteer by promoting web giants as being 'Big Brother', 'friends of criminals' and at the same you have to rebrand the 'Department of NO' (i.e. security) as being 'Mother', 'Keeping you safe' etc. To some extent this is already done but the balance of power is very much with the selling side of consumer services and most users are easily swayed to accept the loss of privacy in return for baubles of use.
I'm not saying you shouldn't be concerned about the loss of privacy and control - you should. But in all likelihood privacy will be a notion of the past. You're in an uphill struggle to prevent what is already evidently happening. Privacy and control concerns are being given away freely through choice in favour of more usefulness even when many of those useful needs are simply figments of marketing's imagination and didn't exist before marketing persuaded us we needed them.
You could take a 'pragmatic' approach of accepting the change and looking at how to minimise any risks but remember the competitive pressures push in one direction, so don't examine today's situation but work from the basis of tomorrow's. In other words, start by considering a world where all user information, even what we would consider today as your 'private' details are not only a matter of public knowledge and discussion but accepted as such - every place you've been, every conversation you had, everything you ever looked at and every detail of your life.
Imagine a world where offers that are publicly promoted to you are influenced by the fact that six years ago you spent 2 seconds looking at a picture in some shop window (rather than the average of 1.5 seconds) and your heart rate increased slightly. Every minute detail of your life will be catalogued and referred to ... apparently, for your benefit.
Now ask yourself what needs to be put in place so that users retain some element of control?
That said, I must now get back to spying on my family with my 'mother' system - it's in their own good you know, the brochure tells me so ...