Many Silicon Valley parents are becoming more concerned about preventing their children from using screens. Some parents think that even a little screen time can be extremely addictive, so it is better if their children avoid using or seeing these devices completely. However, it is difficult for working adults in the 21st century to give up using a phone at home. So, it's simpler to employ someone to do this. 

"Silicon Valley nanny（保姆）", who takes children back to a time without screens every day is widely needed. From Cupertino to San Francisco, it's widely agreed that screen time is harmful to youngsters. Therefore, parents are requesting nannies to keep phones, tablets and computers in a hidden place. Others even offer no-phone agreements.

Research shows that spending too much time on technology can harm young minds. For example, teenagers who use social media frequently are more likely to feel depressed and anxious. Insomnia （失眠）rates have also increased amongst this age group, and an increasing number of children display the signs that they can't focus attention. These seemingly minor（轻微的）problems could become significant challenges for future generations. 

"Many parents come back home and focus on their smartphones, ignoring whatever their children are trying to say," said Shannon Zimmerman, who works as a nanny in San Jose for families that forbid screen time. "As a nanny, I also call on more parents to spend more time with their kids."