This week, Michael Hayden, who headed the CIA and the NSA during the Bush Administration, said that if he’d been on the Supreme Court for the 9 to 0 decision requiring a warrant before cell phone searches, the vote would’ve been 10 to zero. Former Congresswoman Jane Harman also spoke in favor of the ruling. Good for them. Yet both made their remarks during different Aspen Ideas Festival panels where they were primarily speaking in defense of NSA surveillance. Josh Gerstein at Politico has a good summary of why Chief Justice Roberts opinion in the cell phone case may portend a future decision that reins in NSA spying: For the NSA debate, the most significant idea in the court’s Wednesday opinion may be the notion that scale matters. Roberts and his colleagues soundly rejected arguments from the Obama administration that because police can search a few printed photographs found in someone’s wallet, officers were free to search thousands of images and the troves of other personal data contained on a typical smartphone. Government lawyers engaged in the NSA fight have pointed to a 1979 Supreme Court ruling that approved the use of a trap-and-trace device put on a single phone line to investigate harassing phone calls. That decision, those attorneys say, means there is no constitutional problem with authorities assembling data on many — or even all — calls made in the United States. Critics have said the two situations bear little resemblance to one another, in part because of the huge difference in scale. “It’s very important that the court is recognizing that quantity matters,” said Georgia Tech professor Peter Swire, a privacy expert and member of a panel President Barack Obama set up to review the NSA’s call metadata program. “The court has said that quantity matters when it comes to the content of cell phones. And I believe the court will feel the same way when it comes to massive databases of telephone calls or computer communications.” A former cybercrime prosecutor said the justices also seemed to recognize that scale of the collection not only gives the government more data, but also the ability to be much more intrusive than in earlier eras. “The distinction here is more than just the capacity of the device to hold pictures,” said Alex Southwell, now with law firm Gibson, Dunn & Crutcher. “A cell phone is orders of magnitude different, not just in terms of numbers of items held but also in terms of the intrusiveness if searched. The mosaic of information available from seeing the whole of the data is transformative, just like the call records at issue in the NSA program. Amy Davidson has related thoughts for why the cell phone ruling may matter to NSA surveillance. As I wrote elsewhere, "Now that the Supreme Court has decided, unanimously, that it isn’t okay to search an arrestee’s cell phone without a warrant, are they really going to uphold programs that surveils the metadata and Internet habits of millions of people who’ve never even been arrested?" Hayden and Harman would say the Supreme Court ruling affects Americans as they interact with law enforcement, while the NSA is a foreign intelligence agency. But Hayden elides, and Harman doesn’t seem to fully grasp, the degree to which the private communications of Americans are implicated. I used to wonder if the Supreme Court would apprehend the intrusiveness of what the NSA does to ordinary Americans under the status quo. The cell phone case suggests it might. _____ The Aspen Ideas Festival is co-hosted by The Atlantic and The Aspen Institute.