There is also this issue To address this, we will measure Telemetry Coverage, which is the percentage of all Firefox users who report telemetry. The Telemetry

There is also this issue To address this, we will measure Telemetry Coverage, which is the percentage of all Firefox users who report telemetry. The Telemetry Coverage measurement will sample a portion of all Firefox clients and report whether telemetry is enabled. This measurement will not include a client identifier and will not be associated with our standard telemetry. Even if you turn telemetry off it will still call home https://blog.mozilla.org/data/2018/08/20/effectively-measuring-search-in-firefox/ https://blog.mozilla.org/data/2018/08/20/effectively-measuri...