Silicon Valley has been trying to run a mile from the mess that is Theranos. But the debacle at the blood-testing start-up - which the US Securities and Exchange Commission said this week was a "massive fraud" - will not be as easy to shrug off as the powers-that-be in the tech world would like.

It also holds a particular warning at a time when tech start-ups are extending their reach into industries from healthcare to finance and transportation.