Well passing lightly over the fact that Apple's software engineers clearly wasted their time writing an unnecessary firewall, purely in the interests of intellectual enquiry let us imagine an individual so benightedly stupid as wish to use the firewall included in Mac OS to ensure that, for instance all the ports are stealthed and that if someone should get past the NAT mapping (it IS possible, though quite difficult) they can do no damage. Which of the three security levels available would you use and why?
Remember, this idiot is a total pillock and is probably carrying an axe to boot so it's probably wise to humour him. Plus he's even been known sometimes to say please and thank you ...
Put the fun back into dysfunctional.
Mr Punch's Studio