When Silicon Valley tech journalist and entrepreneur Sarah Lacy became a mother, she invited a couple of fellow new parents to her San Francisco home.

“I have a huge TV in my living room, and I think we had a baseball game on in the background - we weren’t even watching it or interacting with it,” she recalls. But then, something curious happened; as the dad, “another figure in the tech industry” held their baby, which began looking around the room, its mother obscured its view of the screen, “no, you’re not going to see TV at all until you’re three years old.”

“She thought the baby being on this couch would be permanently damaging to her child,” Lacy laughs.

This kind of behaviour is becoming increasingly common as many of the tech world’s leading lights, whose products have been used by millions of children the world over, are now intent on curbing their own offsprings’ supply. Not content with banning their children’s devices, they are now legally stipulating that staff do the same – a report last weekend documented the rise in nanny contracts requiring that Silicon Valley sprogs not only be kept away from their own screens, but that those tasked with looking after them don’t use their phones in front of the children, either.