Location: Sydney, Australia.
I would like to know the legalities of harvesting e-mails from
classifieds or any other public places. I was selling my car recently
on www.drive.com.au and withing a few days I was being contacted by
www.tradingpost.com.au with competitive offers. 

Basically the latter company
was picking off contacts and approaching them. Is this legal in
Australia? Is there such thing as public information - i.e. a person
who willingly puts themselves online must expect to be contacted even
outside the original purpose...