Earlier today, the Wall Street Journal published evidence that Google has been circumventing the privacy settings of Safari and iPhone users, tracking them on non-Google sites despite Apple’s default settings, which were intended to prevent such tracking.

This tracking, discovered by Stanford researcher Jonathan Mayer, was a technical side-effect—probably an unintended side-effect—of a system that Google built to pass social personalization information (like, “your friend Suzy +1’ed this ad about candy”) from the google.com domain to the doubleclick.net domain.

Coming on the heels of Google’s controversial decision to tear down the privacy-protective walls between some of its other services, this is bad news for the company. It’s time for Google to acknowledge that it can do a better job of respecting the privacy of Web users. One way that Google can prove itself as a good actor in the online privacy debate is by providing meaningful ways for users to limit what data Google collects about them. Specifically, it’s time that Google’s third-party web servers start respecting Do Not Track requests, and time for Google to offer a built-in Do Not Track option.