States[1], not governments[2]; an often unrecognized distinction. Also, while the layperson might not think about the state having a monopoly on violence, it's not exactly a secret or controversial thing. See the Wikipedia article on the topic[3] and this clip of Barack Obama[4][5].

That Obama clip is somewhat popular with libertarian types, accompanied with some form of, "See! Aha! He's admitting it!". As a "libertarian type" myself (though I try not to use that word to describe myself since it has a muddled meaning), my reaction is more along the lines of, "Well, yea."

[1] https://en.wikipedia.org/wiki/State_(polity) [2] https://en.wikipedia.org/wiki/Government [3] https://en.wikipedia.org/wiki/Monopoly_on_violence [4] https://www.youtube.com/watch?v=kpITpm5NxOE&t=1m54s (not endorsing the source) [5] https://www.youtube.com/watch?v=kpITpm5NxOE&t=1m35s (more context)