PARIS — Only a few weeks after the French Constitutional Council rejected one new tax idea — a 75 percent levy on annual incomes of more than 1 million euros ($1.3 million) — another began percolating through the halls of the finance ministry here: a proposal to tax the collection of personal data on the Internet.

Google and Facebook know that John Doe “likes” wine, is shopping for a Volkswagen and often e-mails Jane Doe. The new idea would require the companies to pay for gathering that information.

Nicolas Colin, one of the authors of a report in which the idea of taxing data collection was floated in January, said the immediate goal would be to promote sound practices for data collection and protection.

While the report does not specify how much revenue the tax would yield, Mr. Colin said it would probably be minimal.