Experts are hitting the Dislike button on the messenger app Facebook launched last month in a bid to capture the 6- to 12-year-old market. And yes, they insist, it is a market.

In a letter to the company, dozens of medical and mental health specialists slammed the social- media giant’s attempt to cash in on kids as young as six as a way to broaden and grow its two-billion-strong user base.

Facebook’s previous minimum age restriction was 13.

The company has countered that Messenger Kids is safer than many other online experiences, and features no advertising. In a statement, Facebook insisted that the app “helps parents and children to chat in a safe way, with parents always in control of their child’s contacts and interactions.”

A safe way to chat - or to data-mine future consumers?

The health experts disagreed. “Younger children are simply not ready to have social media accounts,” they wrote. “A growing body of research demonstrates that excessive use of digital devices and social media is harmful to children and teens.” The logical conclusion? “This new app will undermine children’s healthy development.”

The protest letter was organised by the advocacy group Campaign for a Commercial-Free Childhood. It’s the latest in a series of alarm bells about kids’ unfettered use of digital technology - including a recent call by Apple investors to make the iPhone “less addictive” and academic research released earlier this month showing an inverse relationship between smartphone use and happiness among teens.

Facebook may or may not take action to address these issues. Thankfully, parents don’t need to wait - they can start protecting their children today, with Family Zone.

A powerful, cloud-based solution for managing family screen-time, Family Zone lets parents set effective boundaries to keep kids safe and happy online, across every device, everywhere. Use Family Zone to control access to games and apps, set bedtimes, restrict social media, block adult content, and more.