Every other day, yet another article appears telling us that our privacy rights will be trampled by the ever expanding reach of data mining efforts. Well, they're mostly right and in a non-random state space, that is, if the future is predicated on the past, they (whoever THEY are in your control hierarchy) will abuse this stuff.
In case it is the cops that scare you, you should be aware that their computer skills, their infrastructure and their time are limited quite a bit more than you might think. On the other hand, Google and other super Wal-Marts of data aggregation are out there wheeling and dealing to get ever more interfaces to ever more private data stashes. Google says they will do no evil, but as a veteran of watching companies founded by good people eventually being taken over by people whose only care is for their stockholders, when the price is right, virtues are a commodity. So, yes, it will be your credit agencies, doctors, car and hotel rental websites etc. that will do most of the heavy lifting to get the goods on you. If you were listening, during the State of the Onion speech, The W snuck in one of the pet projects which is to ensure that ALL medical records are digitized. In the name of better access to Viagra, we will surrender privacy about ED to the parapsychologists of crime who want to project trends about criminal inflation based on private deflation. As the song says, "Nobody knows you when you're down and out", but these systems keep track just in case.
So is this trend inevitable? Unfortunately, yes, but if you are worried about the locals, study this. CFR 28 Part 23 provides the guidelines for agencies that want/need to access your records in the conduct of a criminal investigation. We should be lobbying our legal representatives at all levels of government to ensure this is applied properly. Don't rely on the Department of Homeland Security to get this right. They are rather busy figuring out how to make it easier to do. Don't rely on the World Wide Web Consortium to get it right. They are rather busy figuring out how to make it more reliable to do.
The geeks don't care and the suits are going to make more money doing it. If you care, you better vote this issue into being by keeping it in front of your congressional reps and local politicos. There is a a lot of digital ink devoted to scaring you into giving up your rights but there is a lot less to be afraid of and knowing more about you won't help them protect you from them. Criminal investigations don't work that way although bits of emergency response do. In the second case, all they need is your location and a way to call you, email you, or orient you toward that big clanging bell in the town square. They don't need your life history. Total Information Awareness is BS, friends and neighbors. They don't need it to do their jobs. They just want it. That SHOULD bother you.
You should be concerned, but the guidelines already exist and your best protection is to know about them. Hit that link above and do a bit of reading. If you see in a footnote of the back page of your newspaper that they are ammending CFR 28 Part 23, PAY ATTENTION.