A San Francisco supervisor introduced legislation this week to ban the use of small, food-delivery robots on city sidewalks, citing pedestrian safety in the latest battle over government regulation of 21st Century technologies including robots, drones and driverless cars. District 7 Supervisor Norman Yee, who introduced the bill, said his proposed ban is the only one of its kind that he is aware of in the country. He said other cities that have considered similar robot regulation lack San Francisco’s high population density, a factor that increases the risk of a potential accident.

“I know that many companies want to use them right now, but what does this all mean in the future?” Yee said. “It’s cool until we get hundreds, and people get annoyed, people trip, and eventually someone is going to fall—whether they’re elderly or someone with disabilities or a little kid.”