The worlds of geeks and geezers are about to collide. And the tech world is holding its collective breath for possible ramifications that, like any generational clash, could turn ugly.

On the geriatric side, the average age of the U.S. Supreme Court justices is near 70. They don’t use email (let alone Tweet) to communicate; they write memos and, quaintly, send them by courier. They admit they don’t understand social media, much less the cloud.

But on Tuesday they will hear a crucial technology case that will determine how private our geeky smartphones are. It’s likely to be the first in a series of challenges involving technology users’ Fourth Amendment rights governing search and seizure.

Silicon Valley geeks think protecting users’ privacy rights is in the interest of all Americans, young and old. So do we. But our confidence in the court’s comprehension of this issue is thin.

The case involves David Leon Riley of San Diego, a Lincoln Park gang member who was arrested in 2009 for having expired car license tags. The police impounded his car, found loaded guns in it and charged him with possession of the firearms.

Riley was carrying a Samsung smartphone in his shirt pocket. An officer confiscated it and found texts, photos and other information on it that connected Riley to gang members. As a result, he was convicted of attempted murder and assault with a semi-automatic firearm. He is serving a 15-year sentence.

The prosecution hangs its argument on a 1973 court case that allows police to search whatever a suspect is carrying when arrested. The rationale was that police should be able to search for weapons and for evidence that could otherwise be destroyed.

In 1973, that could have included an address book or a note pad. But allowing police to search someone’s smartphone without a warrant is equivalent to letting them search their entire home for all of their personal financial and medical records.

It’s giving police access to intimate emails, texts and photographs between friends, family and work associates. These days, given a choice, most detectives and prosecutors would probably rather search someone’s smartphone than their entire home and workplace.

The California Legislature tried to deal with this issue in 2011, passing a law sponsored by Sen. Mark Leno requiring police to obtain a search warrant before searching the contents of any portable electronic device. But Gov. Jerry Brown vetoed the bill, saying the issue should be decided by the courts.

The Supreme Court justices may not fully understand the capacity of smartphones, but we hope they will by the time the Riley arguments are complete. They should be sophisticated enough to realize that police should not have unlimited rights to peruse and download the contents of Americans’ tech devices without a warrant.