Is Facebook's Messenger Kids app good for children? One group says no.

Getting children addicted to social media is now' Facebook's latest bad lewk.

In an open letter to Mark Zuckerberg, a coalition of children's health and education organizations and individuals have called on Facebook to shut down Messenger Kids on behalf of the wellbeing of children.

Messenger Kids is the parent-monitored chat, photo, and video messaging service Facebook launched in December 2017 for children as young as six years old. The minimum age for regular Facebook users is 13.

Published by the Campaign for a Commercial-Free Childhood and signed by a host of other organizations, the letter argues that introducing children to social media at an earlier age will increase their dependence on digital devices, negatively affect their mental health, and impact their ability to form relationships.

"Younger children are simply not ready to have social media accounts," they write. "A growing body of research demonstrates that excessive use of digital devices and social media is harmful to children and teens, making it very likely this new app will undermine children’s healthy development."

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At launch, Facebook said it developed Messenger Kids as a way for children to safely use social media online. A child's messenger account is linked to their parent's account, with all "friends" pending parental approval, and with dedicated safety monitoring for inappropriate content. The app is advertisement-free, and Facebook also says it won't send children's data and information to advertisers.

So supposedly, with these safeguards put in place, children can use the Snapchat-like app to apply funny filters they send to their parents and friends to their heart's content. All with the thumb's up from mom and dad.

"Since we launched in December we’ve heard from parents around the country that Messenger Kids has helped them stay in touch with their children," a Messenger spokesperson told Mashable in a statement. "We worked to create Messenger Kids with an advisory committee of parenting and developmental experts, as well as with families themselves and in partnership with National PTA. We continue to be focused on making Messenger Kids be the best experience it can be for families. We have been very clear that there is no advertising in Messenger Kids.”

But the letter writers aren't buying it. Instead of providing a truly safe service for children and parents, they see it as a way for Facebook to make inroads with a new — and particularly vulnerable — business demographic.

"Messenger Kids is not responding to a need -- it is creating one," they write. "It is disingenuous to use Facebook’s failure to keep underage users off their platforms as a rationale for targeting younger children with a new product."

The letter also takes Facebook to task for its recent missteps regarding Russian manipulation of the platform for political gain, and for advertiser discrimination. The letter cites Zuckerberg's vow to "do better," and gives the organization a concrete step they can take to make good on that promise.

"Doing better is leaving younger children alone and allowing them to develop without the pressures that come with social media use," they write. "Raising children in our new digital age is difficult enough. We ask that you do not use Facebook’s enormous reach and influence to make it even harder. Please make a strong statement that Facebook is committed to the wellbeing of children and society by pulling the plug on Messenger Kids."

It's reasonable to question the business upside and developmental impact of Messenger Kids. If we've learned anything from Facebook's recent scandals, it's that big tech companies ought to critically consider the societal impacts of their products before releasing them into the world.

But will ending the service make young children less dependent on screens and social media, as the letter's authors suggest? That's an enormous battle that removing one app might not be significant enough to fight.