Six European countries, including France and Britain, have launched a joint action against Google to get the US Internet giant to scale back on new monitoring powers that watchdogs believe violate EU privacy protection rules.
The action came after the EU's 27 member states warned Google in October not to apply the new policy, and gave it four months to make changes or face legal action.
When that deadline expired in February, several European data protection agencies set up a task force to pursue a co-ordinated action against the search engine pioneer.
Among the Google services affected were Gmail, YouTube, the Android mobile system, social networks and its ubiquitous internet search engine.
Cnil also said it had notified Google that it had launched an inspection procedure.
But critics argue that the new policy gives the operator of the world's largest search engine an unprecedented ability to monitor its users.
EU Justice Commissioner Viviane Reding welcomed the move.
"It is good to see that six national data protection authorities are teaming up to enforce Europe's common data protection rules," she said in an emailed comment.
"I am confident that the European Parliament and the EU member states will strengthen Europe's enforcement tools substantially in the course of this year."
Still, the news took little toll on Google's shares, which in mid-day New York trading were 1.12 percent higher at $810.15, while the Nasdaq index of technology shares was up by 1.04 percent overall.