When you go to the Dashboard of your WordPress site, WordPress checks whether your browser is up-to-date, and displays a notice if it is not. However, the browser check is performed by an external site. WP sends such data as: visitor’s user agent string, WordPress version, and the URL of the blog (and, implicitly, its IP address). Unfortunately, there is no way to opt out of that in the Dashboard. Luckily, there is a solution.