You’re sitting in a coffee shop, talking to a friend. Suddenly, the waiter shows up, asks for your phone numbers, and wants to know who else you’re friends with and what you’re talking about. Do you provide the requested information? Would you provide the information if, in turn, you wouldn’t have to pay the bill? Is it safe to assume that you have something to hide if you don’t enter into this deal?
Internet users who disclose their privacy in order to access free online services often do so on the grounds of having “nothing to hide”. However, as closer inspection reveals, this position is untenable. Having nothing to hide might be a desirable state of affairs, but it doesn’t entail that it’s safe to disclose one’s privacy.
If you don’t feel comfortable providing the requested information to the waiter, that doesn’t mean you have something to hide. It simply means you wish to preserve the privacy you rightfully deserve. Maybe you’re discussing something mundane, like the weather, but you think it’s none of the waiter’s business. Also, you don’t know what the waiter might do with the obtained information and why he’s keen on acquiring it in the first place.
If you do not carelessly disclose personal information to strangers in real life, you probably shouldn’t provide the same information to online services, either. By combining several data points, it’s easy to draw a detailed picture of you; one which reveals far more than each data point would on its own – and one that could reveal more about you than you would imagine.