Mozilla has twice carried out privacy & security diligence of the AdObserver, doing both a code review and privacy review of the user consent flow to ensure users understand what they are installing. Our first review was conducted in September 2018, when we examined an earlier version of the extension. That earlier version was subsequently merged with other ad reporting tools, resulting in some changes to the code base. Our second review of the updated extension was carried out in early October 2020 and again involved both a code review and privacy review.
In both cases the team responsible for this add-on responded quickly to our feedback, made changes to their code, and demonstrated a commitment to the privacy of their users.