Fighting subversion is suddenly the talk of Hong Kong. That might surprise visitors to the peaceful, cosmopolitan city, since in democratic countries subversion is rarely prosecuted, even where laws against it remain on the books. But while Hong Kong is supposed to retain the civil liberties it enjoyed as a British colony, there is still the unresolved matter of what to do about Article 23 of the Basic Law. It requires the government to enact laws "to prohibit any act of treason, secession, sedition, subversion against the Central People's Government," among other things. The government hasn't yet introduced such legislation for fear of the controversy it will create, but there are signs the activities of the Falun Dafa [group] are about to be used as an excuse to curtail freedom of speech, religion and association in the territory. Chief Executive Tung Chee Hwa has often repeated Beijing's line that Article 23 is necessary to prevent Hong Kong from becoming a "base for subversion" in China. Then last month Falun Dafa, labeled an [] by the Chinese government, rented Hong Kong's City Hall to hold a convention that recounted many stories of oppression on the mainland. The event evidently infuriated both Mr. Tung and his masters in Beijing. [] That marked the beginning of what looks increasingly like a concerted campaign to paint the Falun Dafa as [], and so pave the way for deregistering the group and introducing new legislation. [] Falun Dafa is a [group] that has attracted hundreds of thousands of members in China and abroad, []. Fearful of losing its stranglehold on civil society, the Chinese government branded Falun Dafa an [] more than a year ago and is now arresting members. However, it has never produced any evidence that could be verified by outside observers that the group is really a []. In Hong Kong, moreover, the local branch of the religion is a legally registered entity, and it has broken no law. Its members occasionally demonstrate peacefully against the oppression their colleagues face in mainland China. But so far it has not called for the overthrow of the Chinese government or taken any actions to that end. That makes it hard to see why there is any need for a subversion law to deal with this group in Hong Kong. And indeed there's no need for the law at all. As in most common-law countries, taking up arms against the government, or even planning to do so, is already prohibited under Hong Kong's laws against violence and conspiracy. Voicing dissatisfaction with the government, on the other hand, falls under the protection of free speech laws and is within the rights of any organization, even religious ones. Indeed, any law which restricted Falun Dafa's ability to criticize the central government would necessarily also catch in its net the Hong Kong press and innumerable local groups, including the Catholic Church and a group which commemorates the Tiananmen Massacre. That would deal a body blow to Hong Kong's way of life, its autonomy and ultimately its economy. If subversion means undermining the values and institutions which underpin a society, then the idea that Hong Kong needs a subversion law fits the bill. Thankfully the city is still a free enough society that this idea can be debated in the coming days. It is to be hoped that the proponents of such a law will be shown the error of their ways.