However, a small company released a personal Firewall product for the Mac in 1999. Originally titled DoorStop Personal Edition from Open Door Networks, it was easy to install and did everything needed to prevent unauthorized access to the Macintosh from the Internet. Recently, this product was licensed by Symantec and is now available as the Norton Personal Firewall for the Macintosh. Personal Firewall even keeps a running log of unauthorized attacks in case you want to try to trace the attempts back to the originator. But don't hold much hope of finding perpetrators since most hackers do a pretty good job of hiding.
FireWalls are defensive at best.
But at least your precious Macintosh data will be safe from prying eyes.