I was browsing r/privacy today and I came across this guy going on about how Mozilla was just pretending to be privacy focused. Here's his comment. Now I don't really know what to think of this, and frankly, I'm getting really exhausted of hearing about how all the things I'm using aren't actually trustworthy. So can so someone put my mind to rest? Does this guy's claims have any truth to them? Thanks.

Here is what just happened to me:
Firefox installed two addons - fxmonitor@mozilla.org.xpi and telemetry-coverage-bug1487578@mozilla.org into my browser silently, even though I've explicitly turned all the telemetry off.
This have happened before, and Mozilla apologized for it, however it seems that they learned nothing and are willing to do so again.
There goes the last scrap of my trust into Firefox. I suggest you check your browsers too.