Ubuntu Security :: None Windows Computers Firewall And Anti-virus Program?

I tried to ask this question in the other thread but the admin was saying to me that my other thread here [URL]..( it was not very much the subject of the thread ) People that use Unix,Mac OSX or any Linux OS all none windows do you need anti-virus program like Norton or Kaspersky? And same with firewall like ZoneAlarm and Comodo ?

Some people say you do not need a anti-virus program like Norton or Kaspersky or any firewall.Other people say you do and some say that Unix and Mac OSX have built in firewall.

And if on uses windows use ZoneAlarm or Comodo has it does alot more than windows firewall and router firewall. Note the admin saying the other thread was why windows get more malware and not very much the subject of the thread to post there.