In the world of American privacy law, one Supreme Court decision casts a long shadow over all others: Katz v. United States

In that decision, which was handed down in December 1967, the court famously held that the Fourth Amendment “protects people rather than places.” Katz countermanded a previous Supreme Court ruling from 1928, which required a physical trespass to prove a Fourth Amendment violation.

In Katz, because the FBI placed secret microphones without a warrant on a Los Angeles phone booth to investigate Charles Katz’ illegal gambling, the Supreme Court reversed a lower court’s decision. The court found that a telephone booth was, in fact, a place (like a bedroom) where a person has a “reasonable expectation of privacy.”

One of the youngest members of Charles Katz’ legal team was Harvey Schneider, then a recent graduate of the University of Southern California law school. It was Schneider who came up with the legal theory that he presented to the Supreme Court:

We feel that the right to privacy follows the individual and that whether or not he’s in a space enclosed by four walls and a ceiling and a roof, or in an automobile, or in any other physical location, is not determinative of the issue of whether or not the communication can ultimately be declared confidential.

The Supreme Court accepted this argument. As such, the entire concept of a "reasonable expectation of privacy" is one that has been raised by nearly every defendant in surveillance cases since, including the recently-decided Graham case.

Since the 1960s, Katz has been used as a stepping stone for other important legal ideas, including the third-party doctrine, which legitimized the National Security Agency metadata program, among other things.

So it was in this light that Ars called Schneider, now a retired Los Angeles Superior Court judge, to discuss Katz and its ramifications today.

In our brief conversation, Judge Schneider said that he was very worried about the presidential election of Donald Trump and his future Supreme Court nominations. As of now, President-elect Trump will have at least Antonin Scalia’s seat to fill since his death earlier this year, and he could have more in the coming years.

“I think the guy’s a moron,” Schneider said of Trump, “and has no idea of what governance is about. He has surrounded himself with people—[Steve Bannon, Trump's chief strategist] is a white nationalist, some of these other people are cuckoo clocks; it’s going to be a tough ride. I have a feeling that privacy is just one of the areas where there could conceivably be an erosion.”

Question everything

Schneider describes himself as a “technological midget” and eschews social media, but he clearly is someone who has spent time thinking about the contemporary implications of a landmark decision like Katz.

When Ars asked him how modern judges should deal with surveillance technologies that we frequently report on, ranging from “network investigative techniques” to cell-site simulators, Schneider urged his fellow officers of the court to ask questions.

“There are judges that sign any kind of warrant without much reflection, and there are judges who will dive into it and ask a lot of questions,” he said. “It differs between judges.”

“It’s not unusual for an issue to be brought to a court that the particular judge has no particular expertise in. I had lots of cases, not necessarily privacy cases, where I did not have any understanding of how certain records were kept, in lots of subjects. The whole process, it’s the lawyer’s job to educate the judge in those subjects. The judge can’t possibly know everything about everything. If it were me and I was asked to sign a warrant, I would be asking lots of questions, but not everybody would.”

Despite Judge Schneider’s privacy interests, he does tend to lean toward believing the government in most situations. He said, for example, that he “wasn’t happy at all about Snowden.”

“To me, national security trumps everything—pardon the expression,” he added. “My premise is that law enforcement is operating in good faith. If not, all bets are off. Assuming that they reasonably believe that there is a communication going to and fro, that somebody is planning on placing a bomb somewhere, I don’t think that they shouldn’t try to get somebody and let the bomb explode. I don’t think that’s necessary. But it has to be in good faith. Aside from national security concerns, I think a reasonable expectation of privacy and warrants should apply.”

Even though he generally seems to give government the benefit of the doubt, Schneider indicated that he’ll be watching the Trump administration with a skeptical eye.

“It may not be pleasant, the next few years, but we will see,” Schneider said.

UPDATE Tuesday November 29 12:08pm ET: The headline and dek (sub-headline) have been edited.