Why would someone deface a multi-million pound artwork?
The Assistant Editor of the Art Review magazine, Oliver Basciano, says there's a long history of artworks being defaced for political and so-called "artistic" reasons.
More top news
Who are the 'Clipperati'?
ITV News London's Chris Paxton is taking part in the round-the world Clipper sailing race. People from across the globe are taking part.
Woolwich heroine 'just talked to a guy who was in need'
A mother who confronted a man suspected of attacking a soldier has exclusively told ITV News she "just talked to a guy who was in need".
Timeline of the attack
How the Woolwich machete attack unfolded, and reactions to the death of a soldier.