A lot of newer phones can be located as long as a battery is in them. So if someone was to carry say both phones on them and someone decided to see what phones were in the car at the time. One could technically associate one with another to ID the person.
RF ids. Not sure how many of you have hear about the RF IDs they want to use as driver license or not.
They can be read as far away as 50ft so far in tests. Personally I am against them especially as passport IDs. A terrorist with $10dollars in electronic pars hooked to a lap top could walk down a street or a hotel hall way or on a plane and Identify every single US citizen.
Not just that if they placed readers near intersections they could use it for monitoring things like speed and so on. Well that isn't bad you say. Yea, but they would be able to see who you are with were you go who is in your house with you....
Not bad enough. Imagine going to the grocery store since not only can police read these things other people as well. Can how many people could use that for tracking or tailing a person. Stores could use it to watch your habits in the store see what Isles you visit the products you stop in front of and so on.