If you drive an On-Star equipped vehicle.
If you have LoJack anti-theft protection.
If you have a ez-pass toll-road (or equivalent) tag on your car.
Any RFID tags on your clothes or any items around you.
Your company badge, drivers license, etc. may have an RFID tag in it. eg. if you can wave your badge in front of a reader panel - that's RFID.
In an urban setting via any number of surveillance cameras.
Good old fashioned tail.
Really, once you become a "person of interest" you're going to be tracked. Heck, just taking excessive steps not to be tracked may make you a person of interest - as in "what is he/she hiding?"
I guess my feeling is, sure, the technology could be used to track you, but it is no big deal when there are sooo many other ways to keep an eye on someone. And that's not even getting into the fancy stuff like aerial surveillance, chemical tagging agents, bugging, wire-tapping, internet monitoring, etc.