content: Therein lies the problem - unless you are personally willing to go and hand-verify the code by hand (and I don't mean look at it, I mean do the mathematical proof of correctness), and I mean all the code, there is no way to be 100% sure it isn't snooping. That said, keep in mind that every foreign government that tries to get some crap into Linux has an incentive to keep someone ELSE from using it against THEM.  Linux is a relatively popular (yes, a small percentage of desktops isn't much, but it's on a lot of servers, used in a lot of countries, and there are even entire cities that run it in Europe) and an alternative to Windows, which is owned by Microsoft, which is under American influence.  So while it's almost certain that there are some subtle flaws put in there deliberately, it is, ultimately, about as good as you can realistically get short of making your own closed-source operating system. At the end of the day you have to trust someone or write it yourself, and even then you're trusting hardware makers not to put firmware in that compromises you in one way or another.  Perfection in this case is just not practical. Regarding Firefox however, I think it might be less of a target than you'd think.  Mozilla is basically trying to destroy itself and bring Firefox down with it, and is being eaten by politics on the inside while it tries to turn itself into a poorly-designed clone of Chrome as it obliterates its niche of people who want to actually control their browser (e.g. install whatever add-ons they want, have add-ons that are capable of really helping to customize browser behavior, etc.).  IMO Chromium is probably more likely to be the government's target, although if a successor fork to Firefox rises that assessment may need to be revised.