Last project I want to mention that was represented (and applied) on the camp is Sputnik. The aim is to show people the potentials and threats of tracking technologies by personal experience. Active RFID tags (newest version v0.2) with different ids were sold to participants and three shelters were equipped with reader stations. The system (2.4GHz based) can track the tags in the range of 100 meters and discriminates between three levels of proximity. With enough stations you can give a very precise position of a person (this was not the case on the camp, but on the congress last year). A button on the chips can be used by the owner to send at signal that something interesting is going on at the current position. The collected data will be available for public use soon.
Due to the fact that only the owner knows the id of his/her tag and that the active chip can be switched off the user can choose the level of privacy. But it still makes people think more about the possibility of total surveillance. Many things like customer cards and passports are already equipped with (mostly passive, low ranging) RFID tags and the rank-and-file is not aware of this. The technology itself (as usual) is not evil. We just have to make sure that it is applied the right way for the right things.