I don't think he would have had any trouble answering Justice Sonia Sotomayor's excellent challenge in a case involving GPS surveillance. She said we need an alternative to this whole way of thinking about the privacy now which says that when you give data to a third party, you have no expectations of privacy. And [Louis] Brandeis would have said nonsense, of course you have expectations of privacy because it's intellectual privacy that has to be protected. That's my attempt to channel him on some of those privacy questions.

He [Louis Brandeis] would have not had any patience with that great debate which you're right to kind of signal between Justice Scalia and Justice Alito about do you need a physical trespass into the home or onto the carriage in order to trigger the values of the Fourth Amendment.

When I was in law school I was taught that the great writers were people like [Oliver Wendell] Holmes Jr. and [Benjamin N.] Cardozo. But you go back and read their prose and it's sort of perfumed and very ornate and show-offy. And they're constantly striving for these abstractions that seem archaic nowadays.

We need to protect the same amount of cognitive liberty in an age where you can invade people's thoughts without physically intruding into their homes than you did at the time of the framing.

[Louis] Brandeis, like [Tomas] Jefferson, is an equal opportunity critic of bigness. And he, like Jefferson, sees American history as this incredible clash between small producers, farmers, and small business people on the one hand, and wicked oligarchs and financiers and monopolists on the other.

Before Sept. 11, the idea that Americans would voluntarily agree to live their lives under the gaze of a network of biometric surveillance cameras, peering at them in government buildings, shopping malls, subways and stadiums, would have seemed unthinkable, a dystopian fantasy of a society that had surrendered privacy and anonymity.

I think the answer has to do with the fact that [Louis D.] Brandeis was a consistent critic of bigness in business and in government.