In UK, the BBC has decided in its arrogant wisdom the plural of certain latin words adopted directly into English that end in "um" shall no longer end in "a" but in "s"

Thus

Stadiums instead of Stadia

And to think that we Brits are threatened with a criminal record if we fail to pay the BBC Licence Fee which is essentially a non avoidable impost.

They are even threatening 90 year olds with prison for not paying!