Those with long memories will know Hotz from his days as Geohot, the hacker that cracked the iPhone and PlayStation 3. The engineer has founded a company, Comma, on the principle that cheap sensors and machine learning makes it possible to make a system for a few thousand bucks. It's a claim that Tesla was quick to trash, saying that while it's easy to build a system for a "known stretch of road," a real self-driving car is a much harder proposition. Still, if the folks at Horowitz are opening their bank accounts, even slightly, then they must feel differently.