A few days after a gunman killed 19 children and two teachers in Uvalde, Texas, a year ago, taser-maker Axon Enterprise floated the idea of a "nonlethal" drone for schools that could be activated by AI-powered surveillance.

It caused a stir — prompting the company's own AI ethics advisory board to quit in protest and highlighting growing unease about the ethics and effectiveness of security tools being marketed aggressively by technology firms to U.S. schools.

"I had to have my secretary screen out the calls from all these companies," said Rita Bishop, former superintendent of the school system in the city of Roanoke, Virginia, recalling sales pitches for everything from drones to AI-powered surveillance cameras and weapons detectors.