Slightly off topic but oh well, here is some useless information for you
I spent the majority of my life in Australia before moving to Moscow to chase some $. So I can speak about Australia.
The majority of those fans singing YNWA were likely to be Melbourne Victory fans Football in Australia is not very popular (Behind Rugby League, AFL, slightly behind Rugby Union) but it has a strong presence which is ever growing. The domestic league is quite popular (Average attendance was close to 13k last season), the Melbourne derby normally sells out, The West Sydney Wanderers sold all the season tickets that are available, they are guaranteed sold out matches all season. Sydney FC got big crowds last season due to Del Piero. A lot of people support an A-League and EPL team.
The Australian National Team (Socceroos) are more popular than the Rugby Union and Cricket national teams which was not the case ten years ago.