A big row has broken out about whether or not fans should be allowed to find out who The Stig from Top Gear is.
The Stig wears a white helmet with a blacked out visor and test drives cars on the popular BBC Two series.
The man who plays him has written a book about his life, in which he reveals his real identity.
But the BBC say The Stig's identity should remain a mystery, and is taking publisher Harper Collins to court to stop the book being published.
Both sides were in court in London on Monday.
In June last year, The Stig took off his helmet on the show and it was Michael Schumacher underneath.
But no-one's sure if The Stig really is the German F1 driver or someone else - or even a combination of different people.
We do know that at least one other person has been The Stig before. In 2002 a driver called Perry McCarthy said he was the secret racer in a book.