DIY RFID
Cheap and simple technologies such as RFID scanners allow objects to be tracked as they move from place to place. The Arduino-based device above cost me less than $50, a few hundred lines of code, and some soldering-iron scars. In signicant quantities, the chips are in the range of pennies.
These cheap white plastic tags contain unique identifiers; similarly functioning tags can be embedded in clothing, in product packaging, or under the skin.
The low cost and easy construction makes it feasible to track the movement of nearly anything or anyone. The mind reels: What will it mean for an author to know what books were placed on top of or under? What will it mean to a parent to know how their child moved around the house on the weekends? Where will we draw the lines over privacy? Over our public identities?