It is now a law, just in case you are wondering what is used and to which extent …

WordPress.com Stats

Data Used: IP address, WordPress.com user ID (if logged in), WordPress.com username (if logged in), user agent, visiting URL, referring URL, timestamp of event, browser language, country code. Important: The site owner does not have access to any of this information via this feature. For example, a site owner can see that a specific post has 285 views, but he/she cannot see which specific users/accounts viewed that post. Stats logs — containing visitor IP addresses and WordPress.com usernames (if available) — are retained by Automattic for 28 days and are used for the sole purpose of powering this feature.

Activity Tracked: Post and page views, video plays (if videos are hosted by WordPress.com), outbound link clicks, referring URLs and search engine terms, and country. When this module is enabled, Jetpack also tracks performance on each page load that includes the Javascript file used for tracking stats. This is exclusively for aggregate performance tracking across Jetpack sites in order to make sure that our plugin and code is not causing performance issues. This includes the tracking of page load times and resource loading duration (image files, Javascript files, CSS files, etc.). The site owner has the ability to force this feature to honor DNT settings of visitors. By default, DNT is currently not honored.


WordPress.com Toolbar

This feature is only accessible to registered users of the site who are also logged in to WordPress.com.

Data Used: Gravatar image URL of the logged-in user in order to display it in the toolbar and the WordPress.com user ID of the logged-in user. Additionally, for activity tracking (detailed below): IP address, WordPress.com user ID, WordPress.com username, WordPress.com-connected site ID and URL, Jetpack version, user agent, visiting URL, referring URL, timestamp of event, browser language, country code.

Activity Tracked: Click actions within the toolbar.