Google Inc. said it is changing its official policy so it can track users across all Google services including email, Web search and YouTube in a move that could invite heavier scrutiny of its privacy practices.
The new policy, which takes effect March 1, affects hundreds of millions of users who log into Google on their desktops or on their mobile devices. The only way to turn off the data sharing is to quit Google.
"If you're signed in, we may combine information you've provided from one service with information from other services," Alma Whitten, Google's director of privacy for product and engineering, wrote in a company blog post. "In short, we'll treat you as a single user across all our products, which will mean a simpler, more intuitive Google experience."
The Internet search giant has shared this kind of information across many of its services for years. Now it is adding YouTube and search history to that mix.
But in the wake of last year's settlement with the Federal Trade Commission and heightened attention to privacy in Europe, Google is looking to spell out its privacy policies and terms of service to users.
It's also stepping up competition with Facebook by getting to know its users better and selling ads more finely tailored to their interests.
For example, a user who has recently searched on Google for skateboard tricks might have videos featuring skateboard pro Tony Hawk recommended on YouTube.
"This may cause more critics to complain that there is no escaping the clutches of Google," said Danny Sullivan, editor of SearchEngineLand.com, which tracks Google.
Also riled are privacy advocates such as Common Sense Media Chief Executive James Steyer.
"Even if the company believes that tracking users across all platforms improves their services, consumers should still have the option to opt out — especially the kids and teens," he said in a statement.
Google's announcement comes two weeks after it came under fire for blending information from its Google+ social network into search results.
Privacy advocates say that Google invaded users' privacy because when they posted on Google+ they did not know the posts would show up in search results.
One watchdog, the Electronic Privacy Information Center, filed a complaint with the FTC saying the new search tool violated the settlement Google reached with regulators last year.
Google used to have dozens of separate privacy policies for all of its products, creating a complex web of documents for users to navigate. Now Google will have just one to cover 60 services. A dozen products including Google Wallet and Chrome will still maintain separate privacy policies.
Google said it has been working since 2010 to make its privacy policies clearer and more concise.
A week ago Google unveiled an advertising campaign in newspapers, magazines and even subways to educate people about privacy on the Web. The company has been running the same campaign in Europe since last year.
Under Chief Executive Larry Page, Google has moved more aggressively to use its position as the dominant Internet search company to promote its Google+ social network.
It's looking to slow the momentum of Facebook and to use personal data from Google+ and other Google products to improve the quality of the experience on all Google services for users and advertisers.
Facebook, on the verge of an initial public offering that could raise $10 billion and value the Menlo Park, Calif., company at $100 billion, has a rich hoard of information about its users and deep insights into their connections and interests.
Facebook and Google walk a fine line between respecting the privacy of users and mining as much information about them as possible, privacy advocates say.
"Sounds like Google's overall practices won't be that different," said Ryan Calo, director of privacy and robotics at Stanford Law School's Center for Internet & Society, which gets some funding from Google. "It's more that Google is owning up to how it thinks and what it does."