After you advance, you get the chance to "buy" items to enhance your character--one of them was a national flag of your choice, which gives you special protections (all flags gave equal protection)
Well, I chose the US Flag to adorn my character and I got so many "tells" from people asking me if I chose the flag because I loved my country or because its simply because its where I was from.
There was plenty of anger felt against Americans on that game, so I finally chose another flag to adorn my character :)