Nothing to hide, nothing to fear -nothing of the sort.

Professor Daniel Solove examines the nothing to hide argument. When asked about government surveillance and data mining, many people respond by declaring: I've got nothing to hide. According to the nothing to hide argument, there is no threat to privacy unless the government uncovers unlawful activity, in which case a person has no legitimate justification to claim that it remain private. The nothing to hide argument and its variants are quite prevalent, and thus are worth addressing. In this essay, Solove critiques the nothing to hide argument and exposes its faulty underpinnings.

So goes the introduction to this pdf paper written in a USAmerican context but with lots of transferable principles to this side of the pond. In fact he argues

that the “nothing to hide” argument—even in its strongest form—stems from certain faulty assumptions about privacy and its value. The problem, in short, is not with finding an answer to the question: “If you’ve got
nothing to hide, then what do you have to fear?” The problem is in the very question itself.

Towards the end of an interesting discussion of what privacy might be, the issue is restated.

the problem with the nothing to hide argument is with its underlying assumption that privacy is about hiding bad things. Agreeing with this assumption concedes far too much ground and leads to an unproductive discussion of information people would likely want or not want
to hide. As Bruce Schneier aptly notes, the “nothing to hide” argument stems from a faulty “premise that privacy is about hiding a wrong.”

Take the effect of surveillance on society as a whole.

Surveillance can create chilling effects on people’s conduct by chilling free speech, free association, and other First Amendment rights essential for democracy.78 Even surveillance of legal activities can inhibit people from engaging in them. It might be that particular people may not be chilled by surveillance – indeed, probably most people will not be except those engaging in particularly unpopular speech or associating with disfavored groups. The value of protecting against such chilling is not measured simply in terms of the value to those particular individuals. Chilling effects harm society because, among other things, they reduce the range of
viewpoints being expressed and the degree of freedom with which to engage in political activity.

Good read if you're concerned about dataveillance and things like the National Identity Register.