Scottish footie club Rangers could be in big trouble - their fans have been accused of chanting remarks that are insulting to people of different religions.
They face a hefty fine and might have to play their next two European home matches behind closed doors, following the charges from UEFA.
But Rangers say they've worked hard to get rid of such behaviour and are fighting the charges.
The club isn't the only place where rude singing is causing problems. Chelsea star Frank Lampard has just signed up to a campaign to stamp out anti-Jewish chanting in footie stands.