I worked in Mozilla previously for like 5-6 years. I think the supporter of Mozilla is a lot more trustworthy with privacy and data, but not Mozilla itself... I think they claiming that they do this and do that, but actually speak louder than action. My personal takes from the upper management is also not that good.

If you were not working with Mozilla Asian area, you know far too less. They had a browser in China that redirect to different website for profit before every connection and some affiliation. By doing so, is it privacy or not? Oh, look at Mozilla Japan volunteers, they shut everything up because things went wrong.