And yet, the NSA literally vacuums up data at monitoring sites like it was going out of style, warehouses it, and then does aggressive data mining of it.
And that's just the USA (and the UK)... Then you have China, which DOES actively use technology to locate and then "deal with" dissidents, and US tech companies all too willing to get in on that action, if it means getting in on the worlds second largest economy.
Depending on the nation in question, the will and motive to do such "house keeping" is very much real. The willingness of companies in countries where that shit is considered evil and egregious, just to increase their shareholder value every quarter, should be very alarming.
Sadly, the complacency of most people ("Oh, that's just to catch child porn dealers and such.. nothing to do with me!" & etc.) turns a blind eye to this trend, and before you know it, shit is gettin real, and people are wondering why big corporations are so eagerly being part of the new terror.
Personally, I would rather that technology created with the intent to facilitate the collaboration and distribution of information and free discussion of ideas, not be used in ways contrary to that, because some powerful people think they can either get rich, or because they get authority boners.
I would be perfectly OK with cookies, being used as reelya says they are intended to be used. (as that *IS* how they are INTENDED to be used.) To that, I would add, that I STRONGLY desire there to be legally enforced isolation on that technology, and for cross-site analytics to be illegal.