Tiananmen Square doesn't fit very easily into a rhyming scheme, but that's the more memorable name for what Billy's hinting at here. The image of the man standing in front of the tank armed with nothing more than a carrier bag full of shopping is regularly cited as one of the defining pictures of recent decades, and the protest and its repression have had a profound effect on China's development.

For a number of weeks, students and other activists had been occupying the square to mark the death of a pro-reform member of the Communist Party hierarchy and to call for greater freedom and democracy. Things gradually got tenser and tenser, and a kind of paralysis set in, until Zhao Ziyang, the moderate Secretary-General who had earlier tried to resolve the situation peacefully, lost out to the hardliners. Rather than pass by the more traditional tear gas or water cannon, they opted to go directly for the tanks and troops option, and on the night of 4 June 1989, they moved into the square.

Carnage ensued both in and around the square - in fact according to the Chinese regime no-one was actually killed on the square, but rather on the side streets around it. This, however, is unlikely to have been of much comfort to those who lost a limb or their life. The exact casualty numbers are unknown, but are certainly in the range of hundreds killed and at least a thousand injured.

Fifteen years on, and in a world where China has joined the WTO, and is lobbying to be allowed to purchase arms from the EU countries, the cynical might ask what relevance does Tiananmen square still have? Well for the 24 people who are still in prison as a result of their actions in 1989, it is still having a major impact on their lives. For the families and friends of those killed, the search for justice revolves not so much around punishing those responsible, which is implausible, but at least having the events reclassified from a "necessary repression of a counter-revolutionary insurrection" to something a little more balanced.

And the situation of freedom, democracy and human rights in China? Things have improved a little, but as the Hong Kong pro-democracy activists and the Tibetans are well aware, nobody could rule out a re-run further south or west...After all, the hardliners and their inheritance are largely still in control. The tactic of offering greater economic freedom while retaining political control is holding for the moment, but Tiananmen square reminds us that while you may not be able to buy free speech with your credit card, many people will still give everything they have to have access to it.