#BBCtrending: Crimea's 'officers daughters' sing for Russia
19 June 2014 Last updated at 16:16 BST
Singing songs at the World Cup is one of the best ways of cheering on your national team in a large crowd. But what happens when the songs become political?
Russia is playing in Group H. Events in Ukraine are being reflected in social media trends around Russia's national football team.
In particular, Crimea being annexed by Russia is the source of inspiration for a number of unofficial World Cup anthems.
Anne-Marie Tomchak of #BBCtrending reports on how the songs are being used on social media to score political points, by both sides.
Produced by Paul Harris.