The regulators’ letter said: “Combining personal data on such a large scale creates high risks to the privacy of users.”
“Therefore, Google should modify its practices when combining data across services for these purposes,” the letter said. It was signed by 24 of EU’s 27 data regulators plus those of Croatia and Liechtenstein.
Google declined to comment.
Google and other large internet groups like Facebook provide free services to consumers and earn money from selling ads that they say are more closely targeted than traditional TV or radio campaigns.
“They may be prepared to test the legal position in Europe to see what they can get away with.”
The tussle with the EU over data privacy comes at a delicate time for Google.
Europe’s antitrust authorities are also examining the company’s business model to see if it uses its clout in search advertising to favor its own services over competitors’ offerings. Google is in talks with EU regulators on the case, and could offer concessions.