For months, Hong Kong's pro-democracy protesters have taken to the streets, their identities concealed behind masks.
But on Friday - in the face of increasingly violent clashes between hard-line protesters and police - the Chinese territory's government enacted a ban on face masks with the help of a colonial-era law which hadn't been used in decades.
The ban came into effect at midnight Hong Kong time (16:00 GMT) - potentially changing the face of the protests.
Because these masks weren't just a way for the movement to hide their identities from police, employers and parents, but also a layer of protection against the tear gas fired into the demonstrating crowds.
But protesters were not going down without a fight: legal challenges have been launched, with thousands of masked activists taking to the city's streets to voice their anger.