Members of a Facebook group that tipped off motorists about speed traps in southern France slammed the "hypocritical" nature of the case against them as their trial opened on Tuesday.
The case, the first of its kind in France, targets 15 suspects, including the group's co-founder.
"Here are the Internet terrorists," their lawyer Remy Josseaume told the court sarcastically in the southern city of Rodez.
"It is hypocritical to put these people on trial while there are many products that inform drivers where radars are positioned and they are legal," he said.
The suspects face charges of helping motorists and motorcyclists avoid speeding fines.
Eight of them also face charges of insulting police officers by referring to them by unflattering bird names on the site.
The Facebook group "Which Tells You Where The Police Are In (the southern French town of) Aveyron" was created in 2012 and has more than 10,000 members.
A message on its site says: "Alert this group if you are in a car and you see a blue (police) van, a radar or police on motorcycles in the Aveyron.
"It won't take you more than 30 seconds and you will be a hero for people who read your message," it says.
Rodez prosecutor Yves Delperie recently said he wanted to "reprimand people who seek to break the law".
But lawyer Josseaume argued that the suspects had not breached the law in any way.
He said while radar detectors were banned and carried a fine of 1,500 euros ($1,900) and a suspension of six points from a French driving licence, the Facebook site could not be termed as such.
The co-founder of the group, Mathieu Chane, said the trial was "hypocritical" adding that the "judges want to make an example of us and create a precedent"
But road safety groups say such sites are dangerous.
"Speed kills and the fact that one is trying to thwart radar controls puts the lives of motorists and others in danger," said Bernard Stasiowski, the head of a local road safety group.
"Such social networks must be stopped and everyone must respect speed limits," he said.