they want the government to stop arresting them when they indulge in their violent hatred of minorities.

Imo, this is opposite of what the Gadsden flag represents. It's a symbol of the resistance to authoritative oppression. I suppose the logic is that these types use it as a symbol of their resistance to the government preventing them from oppressing others 🤮. I suppose if one were to be absolutely accurate, though, the Gadsden flag isn't a symbol of libertarianism, but, rather, libertarianism supports the symbolism of the Gadsden flag.