Because the design of the open-source sandbox does not allow private data to enter it. https://hacks.mozilla.org/2014/05/reconciling-mozillas-mission-and-w3c-em

Because the design of the open-source sandbox does not allow private data to enter it. https://hacks.mozilla.org/2014/05/reconciling-mozillas-mission-and-w3c-eme/ https://hacks.mozilla.org/2014/05/reconciling-mozillas-missi...