It seems like self-driving cars have been five years away for at least 15 years. But now, major players in the industry—like Google spinoff Waymo, GM self-driving unit Cruise, and upstart Zoox—are promising that fleets of fully autonomous taxis are just about to roll out.

"It's a scam," says George Hotz, the 30-year-old hacker-slash-entrepreneur best known as the first person to jailbreak the original iPhone when he was 17. "No one's close."

Hotz points out that every system on the road today requires the driver to pay attention at all times and be ready to take over. He says that companies touting fully self-driving cars without human safety monitors—and sometimes without steering wheels or pedals—are offering nothing more than a "press demo."

Hotz started Comma.ai in 2015 to upend what he views as Big Tech's wasteful and shortsighted approach to self-driving vehicles. Instead of building specialized cars that rely on expensive sensors and follow laser-mapped routes, Comma.ai has created an autonomous driving system that runs on a smartphone, works on most vehicles sold in America, and requires no additional hardware.