In the category of things I didn’t know I was supposed to be worried about, the New York Times says GPS satellites are vulnerable, and they are being messed with by state and non-state actors.

More than 10,000 incidents of GPS interference have been linked to China and Russia in the past five years. Ship captains have reported GPS errors showing them 20-120 miles inland when they were actually sailing off the coast of Russia in the Black Sea. Also well documented are ships suddenly disappearing from navigation screens while maneuvering in the Port of Shanghai. After GPS disruptions at Tel Aviv’s Ben Gurion Airport in 2019, Israeli officials pointed to Syria, where Russia has been involved in the nation’s long-running civil war. And last summer, the United States Space Command accused Russia of testing antisatellite weaponry.

New York Times

GPS is an example of a military technology that has spilled over to enormous worldwide civilian benefit. But it is fragile apparently. The U.S. is actively working (but behind schedule) on a backup system, and this article says many other countries have already implemented backup systems working on towers located on the ground rather than satellites.