As Sweets said, the data itself is neutral. The real problem comes in with who has access to all that data and what they may decide to do with that data. While, yes, there is definitely a certain degree of a caveat emptor element to what the user throws out there, you can't just always blame the user for what can be done with all those details.
We too often have a real blind trust towards others who might have access to our data. In other cases, there's also a lot of data mining and snooping done that we know almost nothing about. Some less innocuous than others while some could be downright devastating in the wrong hands regardless of how innocent any given detail may be. It's really not that big of a deal if some company is only using very basic statistics about the demographics of the type of person who might buy their products. Using your personal information to sell to anyone who wants to buy your personal information for whatever they choose to do with that information is a whole other story. Would you like some Temporance nutcase knocking on your door like a Jehovah's Witness pusher just because you occasionally buy a bottle of wine at your local liquor store? Or maybe not get that coveted job interview because they choose to assume that you might just have a drinking problem regardless of what the truth might be? The potential is there to be totally exploited in any way another may choose from marketing to who gets what job or even used to gather information for some sort of character assassination. Just think for a moment about what the Nixon administration was up to regarding the Watergate break in. Oh, and don't forget the Stasi and how they collected all sorts of very detailed files on their citizens and for what purposes, all without the technology we have today.
It's very important to not always be so naive and trusting in the real world by thinking, 'well, if you aren't doing anything wrong, you shouldn't have anything to worry about'. Sure, we 'shouldn't' but the fact is, just like how numbers can be manipulated and distorted by any good publicity agent, lawyer, politician, sales person, etc., so can any given detail about your personal life by anyone who has an agenda that may not be in your best interest.
Seriously, in many cases, it's none of their damn business! Think about it for a moment; if you end up at a sobriety road stop, would you want Big Brother downloading every bit of data from your cell phone regardless of what they may or may not be doing with it? Today, it may be because you ran a stop sign (even though that is not sufficient cause to extract your data though we see it's been done in Michigan). Tomorrow it's anyone they randomly choose to walk up to on the street if we let them continue to tighten up on us like this. History has proven that this is how Totalitarian societies get, maintain and abuse control. Don't ever automatically assume that 'it can't happen here' because, yes, it can!
There's all sorts of other technologies they (be it corporate, government or otherwise) can use on us that hasn't even been hinted at here. Some have already been developed and are even in use while others are still in the R&D stages. Corporate spying is supposedly a big user of some of this stuff while 'the authorities' are another. Then you have the nosy and possibly even psychotic geek head who have their own purposes. So, yeah, caveat emptor but we too must be vigilant and not let so many others abuse the ability to grab our data just because they can. Of course, when it's brought to their attention they will always claim some high minded purpose like refining your personal browsing experiences to preventing terrorism but, the truth is, that's not always their true intentions. It is our jobs to be informed and take action to protect ourselves, be it regarding our personal use to actively getting involved with various privacy advocates who act to protect our rights. The choice is yours and should always be your choice, not that of anyone with the money and power to exploit for their own benefit however they see fit.
