The only thing I’ll add here is that while this argument is simple, people that aren’t used to thinking along these lines will continue try to draw you into the “hows” of anarcho-capitalism. The immorality of the system they’re advocating may be simply invisible to them until it is demonstrated many times. Be patient. Once “the violence inherent in the system” is evident, you can introduce them to concepts around “how” this sort of society might operate. Molyneux himself has written a book on the subject.