The shocking attack on former Ming Pao editor Kevin Lau Chun-to seems likely to have been the work of those seeking to intimidate journalists who dare to hold the government and powerful people on both sides of the border to account.
Violence of this kind is, lamentably, not unknown in Hong Kong where there have been a number of other attacks on journalists and newspaper publishers who are prominent government critics. This violence represents a kind of "black terror" and it contributes to an atmosphere surrounding the media that is most troubling.
Yet Hong Kong's media remains free in many respects and is certainly in far better shape than its counterparts on the mainland. However, journalists are being removed from their posts, government television licences are reserved for the chosen few, critical media sees pressure exerted by the withdrawal of advertising, and so on.
There is not one big cataclysmic event that demonstrates how media freedom is being eroded; it's more a case of a drip, drip effect that turns into a flood. In other words, the situation is complicated but to make sense of what's happening involves stepping back and asking the simple question: is Hong Kong's media in better shape today than it was, say, 10 years ago?
To evade answering this question, commentators who purport to support a free media try to cast doubt on the credibility of individuals who have been caught up in the media suppression storm. This is the oldest trick in the book because all human beings are flawed, and if you search hard enough, it is easy to find fault. But this is a shameless tactic because it seeks to create a diversion from the real issue of threats to media freedom.
The situation in Hong Kong is complicated because the emergence of a relatively free media has a rather short history. For most of the colonial period, media outlets were far from independent. Newspapers started life in Hong Kong to promote special interests, including the opium trade. As time went on, the most persistent criticism of the government came from media outlets controlled by the Communist Party's propaganda machine. Other newspapers, including this one, had long periods when they slavishly served the interests of the colonial administration.
It is hard to pinpoint when the media changed, but it may have been as recently as the early 1980s when even the government-run broadcaster began to assert its independence, new publications emerged and the public showed a considerable appetite for a free media.
That appetite has not diminished; indeed, it has grown and finds considerable expression on the internet. However, traditional media remain remarkably strong in Hong Kong and the public has high expectations.
This is why many of those who took part in last Sunday's press freedom rally had nothing to do with the media, a point widely misreported by outlets that described it as a "demonstration by journalists". Many people realise that media freedom is hardly an issue only for those employed in the industry; on the contrary, it is a key issue for anyone concerned with the preservation of Hong Kong's way of life. When media freedom shrivels, a precious public safeguard starts to fade.
Media freedom is a bit like clean air; in some ways hard to define but easier to recognise when it disappears. People are aware of the cumulative damage to the environment that leads to high levels of pollution but only really start worrying when they need to don face masks before venturing outside. The absence of media freedom will probably become stunningly clear when it's too late to do anything about it, but we should not wait for this to happen.
Stephen Vines is a Hong Kong-based journalist and entrepreneur