Practical Obscurity: The Privacy You Actually Have in Public
Privacy in public was never invisibility — it was three practical frictions: observation is transient, you are anonymous in a crowd, and attention is scarce. A recording contains no information a bystander couldn't have observed, which is why 'it only captures what others could see' feels compelling; it misses that recording deletes ephemerality while keeping the pixels identical. Recording, facial recognition and automation remove the three frictions one each.
**Practical obscurity** is the privacy you have in public not because you are hidden, but because observing, remembering and collating what you do is *inconvenient*. It is the concept that most privacy arguments about public spaces actually depend on, and the one that recording technology dissolves. ## The idea You are visible when you walk down a street. Anyone may look at you. Yet you behave freely, because: - **Observation is transient.** A passer-by's view exists as one fallible memory and then fades. - **You are anonymous.** Being seen in a crowd is not being *identified*. - **Attention is scarce.** Nobody has the resources to follow you, log your movements, and correlate them. None of these is a legal protection. They are practical frictions, and together they have historically done the work that people imagine "privacy in public" means. The term entered legal reasoning through cases about compiled records: information that is technically public but scattered across courthouses and archives behaves differently once assembled into a single searchable file. The US Supreme Court recognised in *DOJ v. Reporters Committee* (1989) that there is a meaningful privacy interest in scattered public information remaining scattered. ## Why recording changes the act without changing the information A recording of you in public contains **no information a co-present human could not have observed**. This is why the objection "it only captures what others could see anyway" feels compelling. It is also why the objection misses. The harm was never the observation — it is what recording does to it. The same pixels become permanent, perfect, searchable, copyable and instantly distributable to millions. Ephemerality is deleted while the content stays identical. **A camera is therefore not "one more set of eyes."** That framing assumes a human observer, who forgets, cannot be everywhere, cannot identify strangers, and cannot cross-reference. A networked camera with AI attached has none of those limits. The quantitative jump — perfect memory, unlimited recall, instant sharing — is a qualitative change. Surveillance is not observation. ## The three frictions, removed one by one - **Ephemerality** → removed by recording. - **Anonymity** → removed by facial recognition. See I-XRAY: The Demo That Turned Wearable Recording Into Real-Time Identification. - **Attention scarcity** → removed by automation, which is what makes The Mosaic Theory: Why Aggregated Public Data Is More Sensitive Than Its Parts bite. Privacy in public was never invisibility. It was these three frictions, and each is being removed by a different technology at roughly the same time. See Why Camera Glasses Draw More Backlash Than Phones.