I'm confused. So you are wanting to throw away your fan, and have it taken to landfill by the council... but someone else taking it and reusing it so it doesn't go to landfill is a bad thing?

I live in Sydney too and it is pretty well understood that leaving stuff on the side of the road for council pickup is fair game for anyone to take it.

Not saying that the dudes who tried to take the fan were in the right for trying to intimidate you, or getting in your face without wearing a mask, that was wrong of them, but I don't think their assumption that "stuff put on the side of the road to be taken to landfill is fair game for people to take and reuse" is entitled. My family used to do the same thing. We were poor, and sometimes scavenging "one man's trash" would mean we could get furniture we couldn't afford otherwise.