MAC filtering should be done on public wireless networks.
Explanation:
MAC is an abbreviation for Media Access Control.
MAC address is a physical address used by each device for hardware identification.
MAC address contain six 2-digit hexadecimal numbers separated by colons.
MAC filtering is a term used in wireless networks for security as well as privacy purposes.
By applying MAC filtering means that the router is configured so that it gets the MAC addresses of the devices which are to be allowed to connect to the network.
All other devices cannot get attached to the network until their MAC address is saved by the owner into he router settings.
So in this way all public wireless networks can get secure.