News of the latest challenge came after a 13-year-old girl from northern France who went missing for three days finally turned up safe and well at her home at the weekend.
The girl, named Emma in the French press, reportedly refused to tell police or her parents where she had been or whom she had been with, but simply said she had taken on a dare through Facebook called '12, 24, 72' or 'Game of 72', as it is also known.
The game basically involves daring a friend to go missing for a certain amount of time without giving any news to your family and making sure they end up in a real panic.
The Facebook challenge, meanwhile, has left authorities baffled - not least because they've been unable to actually find examples of it online. Rather, they've uncovered plenty of panicked postings from parents who are eager to warn each other about the game.
This one below says "Attention Danger!" and warns of "another stupid game doing the rounds on the net". It tells parents to explain to their children that its better to fail the dare rather have "something tragic happen to them."
Indeed, it appears that a large part of the challenge is to remain secretive about in the act of challenging - and it is only Emma's own testimony that suggests the challenge even exists.
One expert, Magali Duwelz, the president of a group fighting against dangerous games for children, told the 20 Minutes newspaper that the Game of 72 could even be more of a hoax than an actual phenomenon.
Nevertheless, authorities have urged parents with any information to get in contact.
The fact that officials are taking the incident seriously is perhaps unsurprising given France's troubling history when it comes to dangerous social media crazes.
Late last year, French people flocked to challenge one another via Facebook to throw themselves into rivers or the sea or face the "fine" of buying a meal for the nominator. The craze resulted in tragedy when a teenager drowned after tying his bicycle to his leg before riding into a river.
The extremely popular social media game "Neknomination" preceded it, which involved people posting videos of themselves downing alcohol and then nominating others to do the same.
France later cracked down on the game, with a set of health reforms given the green light by the National Asssembly this month seeing anyone who incites others to “drink until drunk” risking six months in prison as well as a fine into the thousands.