I generally agree with most of what's been said in here but at the same time I kinda understand what Andy says.
A lot of people on these forums support Italy though they have no relation to the country what so ever, which is fine, but it's a very 'convenient' team to choose to support and you all have to agree with that. The whole world loves football and most of them can't even field 11 players so the most popular team to support is Brazil. Again, while there's nothing wrong with that, it is a very 'convenient' team to support.
I always support and will always support Sweden in international competitions because I grew up there but in a World Cup like this I generally don't care about any team. I'm supporting the underdogs, African teams (being born and lived there I feel solidarity with the people), Portugal being the exception and I wouldn't exactly call them a 'convenient' team to support.
I know I'm saying a lot while not saying a whole lot

but that's because there really isn't a 'rule' to this. Just be ready for people to raise their eyebrows and explain yourself...or just show them the middle finger (which ever you prefer).