The dispute in this case stems from the definition of a radar-detecting device. In 2012, the France passed a law banning radar detectors and GPS equipment that identified the location of speed cameras, according to The Local. The Facebook group in question started in 2012 to collect photos and locations of the cameras and spot police.
At this time, the page is still up and posting pictures of the cameras. It currently boasts nearly 9,000 members, but it's not clear how many of those are newcomers since the brouhaha.
The area's prosecutor finally got fed up and charged ten of the members with using an illegal device, according to The Local. He claimed that the they breached the law because people could look up the page on their smartphone while driving to access the location of the cameras and speed traps.
That seems like a creative reading of the law to some, but the trial doesn't start until September 9, according to French newspaper Le Figaro. If convicted, the accused could face their drivers' licenses being revoked and each receive a fine of up to 1,500 euros – over $2,000. That's a mighty stiff penalty for using Facebook.