One of the values which makes Hong Kong stand out from other parts of China and, indeed, the region, is the high level of respect generally afforded to freedom of expression in our city. Peaceful protests are a regular occurrence here and there is free public debate of important issues. A recent spate of protests in support of detained mainland artist Ai Weiwei have been unusually creative, taking the form of stencilled pictures sprayed in outdoor areas and the projection of images onto buildings, including the PLA barracks in Admiralty. Such activities have the potential, at least, to amount to a breach of the law. While authorities have every right to investigate any suspected criminal conduct, it is important they do not overact.

The police appeared to do just that when they involved a squad responsible for serious crime in their criminal damage investigations into the stencilled images. Although security chief Ambrose Lee Siu-kwong stressed that police were investigating only because of complaints from property owners, the involvement of such a squad in an investigation into graffiti raised eyebrows. It created a perception that the police were trying to send a warning to other similarly-inclined artists. Ironically, it may have encouraged others to carry out such acts. The People's Liberation Army suggested Hong Kong law was breached when an activist projected the artist's image, in what is called 'flash graffiti', onto the PLA barracks in Admiralty. A garrison spokesman said no one could paint or project pictures and images onto the outer wall of the barracks without permission and that the garrison reserved its rights to pursue legal liability.

Article 12 of the Garrison Law stipulates that the Hong Kong government and PLA shall work together to protect military facilities in Hong Kong. So far, there is no evidence to suggest that the military compound has suffered any real threat or material damage. Ultimately, whether an offence has been committed is a matter for the police and courts to decide. While the law must be complied with, there must be no erosion of freedom of expression, fundamental to the 'one country, two systems' concept.