San Francisco’s anti-tech backlash has a new target: robots. This is a place that ought to love artificial intelligence. After all, Silicon Valley is home to some of the most advanced robotics labs in the world. But when it comes to sharing its sidewalks with these technological wonders, San Francisco has said, “Forget it.”

The city recently cracked down on delivery robots — autonomous devices such as those tested by Yelp’s Eat24 service last year, that travel on the sidewalk to distribute food and other essentials to customers. New rules limit them to a speed of 3mph, and require a human operator nearby. Moreover, only nine delivery robots can be tested in the city at any time, dashing the hopes of start-ups that had envisioned fleets of self-driving bots taking hot pizza to hungry millennials.

Like many Silicon Valley innovations, the robots have found their least welcoming audience at home. In fact, several of the city’s most prominent start-ups have faced some of their toughest opposition here.