Lesson 17 - Privacy 5:

Privacy and the Fourth Amendment, Part 2

As we saw in the previous post, Justice Brandeis argued in a famous dissenting opinion that in order to preserve the protections of privacy embodied in the Fourth Amendment, the constitution must be viewed - =ECupdated=EE - to account for changing technology.

Forty years later, the Court followed Brandeis' advice. It changed the nature of the "privacy" that the constitution protected. In a case called Katz v. United States, the Court said the constitution protects "people, not places." The test was not whether property had been invaded, but whether the person has a "reasonable expectation of privacy." "Reasonableness" was to be an objective test - the question was what most people would think reasonable, not what a particular person thinks is reasonable.

Katz seemed a more privacy protecting approach, but the history after Katz has been less certain: Here are some examples. How would you have decided these cases? Do you have a reasonable expectation of privacy in:

your bank records?
(No: United States v. Miller)
the movement of your car, tracked by a homing device attached to the car?
(No: United States v. Knotts)
stuff you have stored on open fields? (No: Oliver v. United States)
your garbage left on the street to be collected? (No: California v. Greenwood)
the stuff the police can see with an aerial flyover? (No: Dow Chemical Co v. United States).

The pattern here is plain, and it is plain why this is this pattern: These rights of "privacy" are decided primarily in the context of criminal cases, where the court must weigh the interests of society against the interests of an alleged criminal; in this balancing, there is always a pressure to protect society, and through a collection of such balances, there is an inevitable shift of privacy protection. The rule seems to be that as technology improves, so that the police can see more without interfering with what individuals do, the constitution is read to allow the police to see what the machines allow.

Next: more on privacy and the Fourth Amendment.

authors:

Larry Lessig David Post Eugene Volokh

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