PARIS -- Is it impolitic to ask the French privacy regulator a personal question about her Internet habits? Perhaps, but Isabelle Falque-Pierrotin, head of the country's data protection agency, is perfectly forthcoming in her answer.
"Facebook? I follow it but, to be perfectly honest, I don't use it," she said. As for Google, "Of course I use it, but I am prudent about what I do. I don't give away any family secrets."
Both Facebook and Google, along with a range of other Internet companies, have faced the scrutiny of Ms. Falque-Pierrotin and her colleagues at the Commission nationale de l'informatique et des libertés, also known as the CNIL.
European privacy officials worry that the mining and blending of data across different Google services, like the search engine and the YouTube video site, could result in privacy violations.
In an interview last week at the CNIL headquarters in Paris, Ms. Falque- Pierrotin said she wanted Google to report back with proposed solutions by February, nearly a year after the new policy was introduced. If the proposals are insufficient, she said, "we will move on to a sanctions phase."
"This is not about taking the scalp of a big company," she said. "It's about pushing them to come into conformity. If a company that is at the heart of the digital economy cannot come up with a satisfactory solution, that is very serious."
Google has said it has been reviewing a letter from Ms. Falque-Pierrotin to its chief executive, Larry Page. The company has consistently maintained that the new policy respects E.U. law.
CNIL has the power to fine companies as much as €300,000, or about $382,000, for violations.
Companies like Google are eager to use the personal data gleaned from the Internet in new ways to sell online advertising and to provide other services tailored to individual users.
But Ms. Falque-Pierrotin said her tough approach was justified by the importance that the French, and Europeans more generally, attach to privacy.
"In Europe, we consider privacy a fundamental right," she said. "That doesn't mean it is exclusive of other rights, but economic rights are not superior to privacy."
In the United States, she said, despite signs of a new concern about privacy in the digital age, "personal data are seen as raw material for business."
The inquiry illustrates a new level of cooperation among the various data protection agencies in Europe, which have sometimes struggled to respond in a consistent way to the challenges of regulating global Internet companies like Google and Facebook.
Viviane Reding, vice president of the European Commission, has proposed the creation of a central authority to oversee data protection at the E.U. level. Big Internet companies have generally welcomed this approach, saying they find it difficult to deal with a welter of local regulations.
Ms. Falque-Pierrotin said, however, that this approach would be "too centralized," adding that she preferred to maintain the current decentralized system of regulation, but with greater cooperation among national agencies.
"We have to have a system where a citizen can go to their local data protection authority," she said. "Otherwise it is too remote."
Ms. Falque-Pierrotin has also been meeting with her counterparts at the Federal Trade Commission in Washington, which is responsible for data protection in the United States.
Even though the American approach to privacy has traditionally been more accommodating, she said that she had been encouraged by recent enforcement action by the F.T.C. against Google and Facebook.
"We are starting to learn, starting to get to know each other," Ms. Falque-Pierrotin said. Just do not turn to Facebook for her biography.
This article originally appeared in The New York Times.