The Eye of Big Brother is poised to spot you, all day every day, even if you don't wear the modish ankle decor which Roman sports these days.* At least he knows he is a scorpion in a glass cage because he rapes little girls.
All you do is use the normal accessories of 21st Century life, cell phones, the Internet, etc. Turns out that Sprint/Nextel thinks it's quite nice to let the cops in on the secret of where you go, when you go there, and how long you stay. In case the cops get curious about why, the nice IT kids have whole departments to scoop clues to the government snoop -- emails, texts, google search terms, all that.
Do I hear in the distance, "Pitch forks, peasants, pitch forks."?
*And , come to think of it, even if you live in a city which hasn't yet decided to circumvent all guarantees of the Constitution and install traffic surveillance cameras which permit the picking of your pocket without the inconvenience of courts and judges and such.
H/Tip to Tam
EDIT: I need to add a credit.