The minute you step out the front door any concept of privacy is a myth.
Satellites are taking aerial photos, Google's cars are driving by taking street view pictures, the government has 'traffic cams' on virtually every corner that can theoretically track all your movements using your license plates or facial recognition, and those electronic toll paying devices like 'Fast Track' are now being used to monitor activity unrelated to toll paying such as speeding or movement tracking in general. Not to mention the red light cameras snapping photos all over the place, cameras in every store taking your picture and listening in on conversations every minute of every day.
The phone in your pocket broadcasts your exact location and if that's not bad enough, some idiots use GPS-based exercise trackers to let others see exactly where they are on foot, bike, etc. and worse yet, broadcast their location to the world via twitter and foursquare but cookie tracking is where we draw the line.
Sure, let's start there ;)
A 15 year old girl recently received pregnancy related offers in the mail
The most important issue in your example IMO is it was a 15 yo minor
. They shouldn't be sending anything to a minor
without parental consent, which is a bigger issue than the privacy part. Dad has bigger issues with his daughter IMO than Target sending her offers in the mail, perhaps focusing more on being a Dad in the first place, teaching about birth control, keeping the kid home, etc. and those offers wouldn't be in the mail to start with but of course we should blame Target about privacy issues that came to light because of his incompetent parenting skills. I'm sure Dad had no part to play in that little problem. TBH, I'd be embarrassed, mortified to be exact, to even tell someone that my crappy parenting skills resulted in such a situation in the first place.
However, If you pay in cash and don't use any store loyalty cards the store has no clue who you are. I often pay in cash in many places and do so exactly so the store doesn't know the name of the alcoholic sex maniac that buys all the booze and condoms every week.
Why are people giving stores their personal information? Let me guess, probably a store credit card, which records everything you purchase by default and will need to continue to do so for proof of purchase in any credit card disputes. Don't spend what you can't afford, pay with cash, and privacy isn't a problem, nor is increasing debt but that's another discussion.
Easy solution: burqa
If you've never disclosed your name to them and always pay in cash they won't have a face to compare in their facial recognition database unless someone else is supplying the faces like Facebook.
Then again, if you didn't give your face willingly to Facebook...
That's where I think you'll see privacy issues really hit the fan because you may not upload your image, you may upload nothing or perhaps a cartoon image. However, suddenly you get notified you've been tagged in some photo uploaded by some other idiot and now the cat's out of the bag anyway. Better yet, if they upload your photo and tag it on some service outside your legal jurisdiction you have no real recourse whatsoever unless you just love throwing baskets of money out the window while tilting at windmills.
Oh well, I could rant about this for a while but I need to go brush my teeth so they look nice and white when I look up and smile for satellite photos and the traffic cams tracking my every movement when I go out for lunch later. Not to mention I'll have fresh breath for Sprint, assuming they can sense such things in the latest smart phones, as I sure wouldn't want ads for mouthwash and breath mints suddenly popping up on my phone...