This is not my idea – I saw it on a site, possibly Fark, today – and the original was worded much better than this half-remembered paraphrase, but hopefully it’ll survive my mangling: Not wanting ID cards or over-the-top state surveillance isn’t because you’re up to no good; it’s about privacy, the same way you put curtains on your windows. You don’t have curtains because you’re up to no good; you have them because having people staring into your house is annoying and occasionally creepy.