Tech billionaires' strict rules for their children

His three children, now 16, 19 and 22, were banned from using mobile phones until they were 14. They were also banned from using them at the dinner table, and were given limits on their usage.

Gates once told the Mirror that his children often complained that their friends were getting phones much earlier, but their pleas did not make him change his parenting rules.

In a separate interview with Matt Lauer, and later on the Today Show, he said he doesn't go as far as keeping his kids' Facebook account passwords, but that online safety is “a very difficult issue for parents today.”

Smartphone overuse – or “phone addiction,” according to some psychologists – is becoming a growing concern for parents, academics, and even those working in Silicon Valley.

Bill Gates' views on technology use are similar to those of Apple founder Steve Jobs. Steve also did not allow his children to use mobile phones at home.

“We limit our kids' technology use at home,” Jobs told the New York Times shortly after the iPad's launch in 2011.

“What do these tech entrepreneurs know about their products that consumers don’t?” ask educators Joe Clement and Matt Miles, co-authors of a book on the subject.

The answer is that it is addictive. Over the past few months, a series of Silicon Valley executives have revealed the power of Apple, Facebook, Google, and Twitter to capture users' attention through their products and platforms.

“It really changes your relationship to society, and to each other,” says Napster founder and former Facebook president Sean Parker. “It can interfere dramatically in the strangest ways.”