One Colorado man has decided that age 13 seems like a good cutoff.
In February, he formed the nonprofit PAUS (Parents Against Underage Smartphones) with a few other medical professionals and began drafting a ballot initiative that, if passed, would make Colorado the first state in the nation to establish legal limits on smartphones sales to children.
Though Farnum's campaign only targets smartphones-the organization writes on its website that "good, old-fashioned cellular phones with voice, Global Positioning System and, yes, even texting are not included"-kids' usage of mobile devices in general are on the rise".
Farnum and his allies have proposed Initiative 29, which would forbid stores from allowing the sale of smartphones to anyone under 13-or anyone who indicates the phone will be owned by anyone under 13. Farnum is a doctor and tells The Coloradoan that smartphones are bad for young brains.
At home, Farnum's two young sons no longer have smartphones - at least for now.
But already, the idea has ruffled feathers across the state.
Farnum said that his campaign was inspired after he watched his own kids struggle with the impact of always having a device in their hands.
"They would get the phone and lock themselves in their room and change who they were", he said.
When Farnum would try to take away their phones, it would trigger aggressive temper tantrums.
"You have cognitive damage, social damage, speech and language problems, attention-deficit disorder - and all these things have accelerated in the last ten years, since smartphones". "The apps are all created to addict you".
"Frankly, I think it should remain a family matter".
'I know there have been different proposals out there regarding the Internet and putting filters on websites that might put kids at risk.
"Ultimately, this comes down to parents ... making sure their kids are not putting themselves at risk", he said.
Enforcing the proposed law could also present a logistical nightmare, he said. The ban would require retailers to ask customers the age of the primary user of the smartphone and submit monthly adherence reports to the Colorado Department of Revenue. Cellphone providers who fail to ID potential buyers or who sell a smartphone to a preteen would then be hit with a violation warning, followed by a $500 penalty that would then double for each additional violation.