The Firefox Health Report is a new system weve built to log basic health information about your browser. It will then give you tools to understand that information and fix any problems you encounter. The initial report is pretty simple, but it will evolve and grow in the coming months. The health report is enabled by default in Firefox but, if you dont want your browser health information added to the pool, you can disable it from the report itself, or from the Firefox preferences window.”]
Source: https://blog.mozilla.org/futurereleases/2013/05/14/firefox-heal-thyself/