I think this is a false dichotomy. In reality, your life is not either an open book or a closed one, and you can choose how much personal information of what type you share with whom. The problems usually start, IMHO, when others are allowed to make that choice for you.<p>This can be direct, as with all the modern tracking technologies and personal information that businesses try to collect about you even if they don't really need it, but it can also be more subtle, for example where social networking sites can build up a profile on you based on information implied by your relationships, or where information from sources you might expect to be independent is aggregated and available for data mining by a single entity. It also cuts both ways, if you wanted to share certain things but for some reason were prevented from doing so, leaving others with incomplete or out-of-date information even though you were willing to share that kind of data with them.<p>I think the more serious problem here is that this is a Pandora's box problem. Once your life is out in the open, there is no way to put it back, but the consequences are not always immediately obvious.<p>Perhaps as a society we should grow up and learn not to evaluate people based on isolated data or out-of-context incidents that we find out about their past, but as any politician, insurance company or judge can tell you, that's not going to happen any time soon. It's probably a generational shift if it's even possible at all.<p>In the meantime, an entire generation are growing up sharing their lives on Facebook and Twitter and being physically tracked via their mobile devices and travel smartcards and logging every purchase/refund they ever made with credit/debit/loyalty cards. It's only a matter of time before "bad candidates" don't even get their CVs read because the employer's automated background checks picked up a black flag, "bad customers" (who expect the product/service they paid for and complain if they don't get it) see their consumer rights eroded by the power of the database, "bad clients" can't get useful or even legally required insurance because their profile fits a high risk group, and so on. These trends are already well established, but as Pastor Niemöller explained, first they came for the communists and I was not a communist...<p>An amusing anecdote to close with: just a few hours ago, I read a comment by someone who works at Facebook, observing that most people there also maintain a separate LinkedIn profile because they want to keep their personal and professional lives separate. Apparently Zuckerberg hires a lot of people who, in his judgement, have a "lack of integrity".