Drones, in my mind, make it clear how many of our feelings about privacy rest on the assumption that surveillance is time consuming or difficult. If someone smokes a joint in her backyard, she is making the (pretty good) calculation that a police officer is not watching. In our cars, we assume we can quickly send a text message at a red light or not wear our seatbelts for a few minutes or drive a few miles over the speed limit. We don't expect that someone is watching our every move and that gives the law some give, a bendiness that reflects it's a human construction.

But these little flying video and audio recorders, paired with powerful data analysis tools, make previously unthinkable levels of surveillance possible, even easy. Before the Internet, tracking someone's reading and shopping activities would have been nearly impossible without a private detective. Now, new online tracking tools make it possible to easily capture every page that you visit on the Internet. So companies do. Technology doesn't create entirely novel privacy questions, but it tilts the playing field towards or away from increased privacy without many citizens (or courts!) really noticing that anything had changed.

Let's look at one example of how drones change the privacy equation. We tend to think of our homes as having a perimeter. Property maps are two-dimensional, we talk about property lines as if they were burned into the ground. There are access points in two-dimensional space -- paths and roads -- that channel visitors through a small number of places. We can build fences or plant hedges and they need not be high to mark the territory out.

A flying drone with a zoom lens, though, makes that whole sense of two-dimensional privacy an anachronism. If one wanted privacy from the government or other citizens, one would have to defend the entire volume of airspace reaching up from one's property to several hundred feet up, if not much farther. This vastly increases the cost of physically hiding one's activities. And, vis a vis law enforcement, the idea of "plain sight" hardly even makes sense anymore, as Jonathan Zittrain pointed out yesterday:

The prospect of constant government surveillance of citizens through cheap drones tests the "plain sight" doctrine by which, under our Constitution, police are generally allowed to scope out whatever is in plain view, without requiring a warrant. Supercharged technologies face some limits -- extra-sensitive remote microphones, or heat signature detectors of the sort that might be pointed at the wall of a home to detect marijuana-growing lamps in use inside.



If a drone with a zoom lens happens to be cruising by your 100-acre farm and spots you smoking a joint on it, were you in plain sight? What if it were technically outside your property line or far above it?

Calo doesn't think we can look to the current body of privacy law for much help in keeping our lives private.

There is very little in our privacy law that would prohibit the use of drones within our borders. Citizens do not generally enjoy a reasonable expectation of privacy in public, nor even in the portions of their property visible from a public vantage. In 1986, the Supreme Court found no search where local police flew over the defendant's backyard with a private plane. A few years later, the Court admitted evidence spotted by an officer in a helicopter looking through two missing roof panels in a greenhouse. Neither the Constitution nor common law appears to prohibit police or the media from routinely operating surveillance drones in urban and other environments. [emphasis mine]



Yet we know that if drones are operated in populated areas, they will end up doing all kinds of collateral surveillance. And nothing legal stands in their way.

If anything, observations by drones may occasion less scrutiny than manned aerial vehicles. Several prominent cases, and a significant body of scholarship, reflect the view that no privacy violation has occurred unless and until a human observes a person, object, or attribute. Just as a dog might sniff packages and alert an officer only in the presence of contraband, so might a drone scan for various chemicals or heat signatures and alert an officer only upon spotting the telltale signs of drug production.



Calo, for one, is not despairing. The types of privacy issues drones create are easier to parse than ones that occur between you and your web browser, so are more likely to create a public outcry. Online privacy violations "tend to be hard to visualize."

Maybe somewhere, in some distant server farm, the government correlates two pieces of disparate information. Maybe one online advertiser you have never heard of merges with another to share email lists. Perhaps a shopper's purchase of an organic product increases the likelihood she is a Democrat just enough to cause her identity to be sold to a campaign. At most one can picture the occasional harmful outcome; its mechanism remains obscure.



But drones are a whole different story, Calo argues. If drones were to come into common usage, "people would feel observed, regardless of how or whether the information was actually used," he wrote. "The resulting backlash could force us to reexamine not merely the use of drones to observe, but the doctrines that today permit this use." In other words, perhaps the creepiness of drones would cast wider doubt on the enterprise of personal data collection.