In its end-of-June rush of decisions, the U.S. Supreme Court delivered privacy advocates a win by concluding that the government is constitutionally required to get a warrant when it wants access to a week’s worth of the location records cell phone companies store about their customers’ movements. But it took more than a decade of ambiguity and dozens of court cases for the public to get this level of clarity about what law enforcement needs to do to access these records.

This raises the question of how many other technologies are being used that we don’t know about, or that are being used under unclear legal standards — and what we can do about it.

As the court observed, there are 396 million cell phone accounts in the United States but only 326 million people. It’s not as though the technology is new. So why did it take so long for the Supreme Court to weigh in? And what about all of the other types of surveillance technology law enforcement is — or will in the future — use to track our movements and communications?

Several factors line up to create and foster law enforcement secrecy around surveillance technologies and slow down court review of even widespread investigative techniques. First, the government actively works to keep surveillance techniques secret. This is understandable to some degree. It doesn’t want suspects to know about tools it uses to catch them. But when surveillance technologies are novel, and push constitutional boundaries, this secrecy means law enforcement uses some technologies for years without anyone outside of policing circles knowing about them.

Second, even when a statute might require the government to get court approval (although not a full warrant) for certain electronic surveillance technologies and techniques, it virtually always does so in a proceeding that is wholly secret and wholly one-sided. Judges simply may not notice that what looks like a minor change in a government application is actually constitutionally significant. And because only the government is involved, the court won’t be able to rely on an opposing party the way it normally does to help point out flaws in the government’s arguments.

Third, many investigative targets never learn that they were surveilled at all. The government generally isn’t required to tell them. Given that some 97 percent of federal prosecutions end in guilty pleas without a trial, there is little opportunity for a judge to rule on the constitutionality of the government’s surveillance.

These are just some of the reasons why it can take decades between when a technology is introduced and the Supreme Court rules on its use — and why the first published magistrate judge decision about cell site location information was issued in 2005 and it took the Supreme Court 13 more years to address how the Fourth Amendment covers cell phone location information.

The delay isn’t all bad. You wouldn’t want the court to weigh in too hastily on a technology while it was still evolving and get it wrong. But it’s a matter of degree. There are many other kinds of data we share with mobile carriers and with other online platforms — and hosts of unanswered questions about when the government can obtain this sensitive and valuable information. The longer courts wait, the longer rights violations continue unabated.

There isn’t one grand solution to this problem of lengthy delays before courts resolve issues of how to apply long-standing constitutional standards to new technologies, but there are some smaller steps that would help.

First, magistrate judges grappling with new technology could issue special invitations to civil liberties groups to file briefs when they face novel surveillance issues — rather than hearing from the government alone. This has happened already to some degree but could be better institutionalized. The Foreign Intelligence Surveillance Court, the most secretive of courts, now has specially designated “amici” advocates. If we can do it for sensitive national intelligence matters, then surely it can work for run-of-the-mill criminal investigations.

Second, there is already a genuine grassroots movement supporting more democratic transparency and accountability for surveillance technology. As I’ve written about in my academic work, too often police departments relying on federal anti-terrorism funds acquire surveillance technology without bringing local elected representatives into the loop. Because this technology is then primarily used for law enforcement purposes, it has a big effect on routine policing, which local elected representatives are charged to oversee.

Cities from Seattle to Somerville, Mass., and a growing number of communities in California have adopted surveillance transparency ordinances pushing for public discussion and debate before adoption of surveillance technology.

And California is poised to become the first state to adopt this requirement for local law enforcement agencies across the board. SB1186, which would require law enforcement agencies to acquire surveillance technology in an open democratic process, has already passed the state Senate and will reach the final stages of Assembly approval in August.

Measures like these will allow elected representatives to put the brakes on projects that are out of step with community values — as Oakland did, when it quashed a federally funded “domain awareness center,” and as Seattle did when it grounded a drone the local police had secretly purchased — while also putting criminal defense attorneys on notice about what technology is available so they can defend their clients appropriately.

It’s 2018. Digital technologies have been woven into the fabric of daily life for more than a decade. It’s time for courts and legislatures to start resolving at a more rapid pace the circumstances under which our cell phones and smart appliances will also be snitches.

Catherine Crump is an assistant clinical professor and director of the Samuelson Clinic for Law, Technology & Public Policy at UC Berkeley, School of Law. Megan Graham is a clinical teaching fellow with the clinic. To comment, submit your letter to the editor at SFChronicle.com/letters.