I knew a few back in college but good Lord they were naive. He was a sweet kid but one of them thought we can get rid of the military and just use mercenaries.

"The Moon Is A Harsh Mistress" by Robert A. Heinlein. It's a really good science fiction novel and the handbook for a lot of Libertarians.

You can read and enjoy it as a story, but if you examine it you'll see all the hoops the author had to jump through in order to make his society work.

One of the most glaring examples is that there are almost no guns in a prison where machine tools are readily available.