"If it does apply, it will probably only cover messages posted by WA "
There are Australian laws that apply specifically to cyber-racism.
see:
http://www.hreoc.gov.au/racial_discrimination/cyberracism/index.html
and
http://www.hreoc.gov.au/racial_discrimination/publications/cyberracism_factsheet.html
Does the Racial Discrimination Act (RDA) apply to racist websites?
Yes, the Racial Discrimination Act 1975 (?the RDA?) does apply to racist websites.
