[ippisl]

What I don't get is: it is theoretically possible to build at least some technologies that offer anonymity together with personalization. Google don't seem to do it.

Is it because they tend to support the government position that we need this data to fight terrorism? Or because they think that I'd they'll use such technology, the government will change the rules forcing them to use the less private tech? Or just plain profit maximizing - do the easiest thing that will bring the most money?