By default,the Safari browser blocks third-party cookies, which companies use to track users habits across the Web. But it does allow for some tracking for convenience purposes, such as when a user submits a form on a Web site or wants to “Like” something on Facebook. By design, once Safari accepts a cookie from a domain like facebook.com, it begins to accept more cookies from the same site.
Google has said that it used the workaround to attach a temporary cookie to users’ machines to see whether users were signed in to its services. If so, the cookie allowed Google to serve them personal ads or gain the ability to use its “+1” button. Google said that it was unaware that that further cookies were being attached to users’ machines.
Google’s tactics were first reported by the Wall Street Journal.
Rachel Whetstone, a Google spokeswoman, said, “The Journal mischaracterizes what happened and why. We used known Safari functionality to provide features that signed-in Google users had enabled. It’s important to stress that these advertising cookies do not collect personal information.”
Google has since begun removing the cookies, Whetstone said, because the company never intended for additional cookies to placed on users’ machines. She added that anyone who has opted out of its Web-base advertising program was not affected.
Apple did not immediately respond to a request for comment but told the Journal that it is working to stop the circumvention.