Perhaps the most unremarked aspect of the stand-off in Beijing, when eight members of the United Front Against the Provisional Legislature were turned back without being allowed to present their 60,000-signature petition, is how the protesters managed even to get on the tarmac of Capital Airport. Some certainly never expected to do so, predicting they would be turned back at the Dragonair check-in desk at Kai Tak. The fact that their travel documents were in order would not have prevented this. When dissident labour activist Han Dongfang tried to fly to Beijing in 1993, all it took was a fax from the Xinhua News Agency stating his mainland passport had been cancelled for Dragonair officials to prevent him from boarding the flight. This is standard international practice, since no aircraft will carry a passenger who lacks valid travel documents. It is also convenient for China, since it forces others to do the dirty work, and avoids the sort of media circus that developed last week in Beijing. But mainland authorities passed up the opportunity to exploit this escape route last week. Rather than inform Dragonair that the protesters' home visit permits had been cancelled, which would have almost certainly led to them being halted in their tracks at Kai Tak, Xinhua instead chose only to issue letters warning that they would have to face the 'consequences' of their actions. Mainland officials must have been aware that this was too vaguely-worded for Dragonair to bar the protesters from boarding last Monday's flight. This strongly suggests a policy decision was taken to allow them to try to enter China. It is not entirely clear why Beijing chose to do this, and so generate large amounts of unfavourable - and unnecessary - publicity. Some clue is offered by the very public way in which border officials brandished the blacklist used in denying the protesters entry. China's Foreign Ministry felt compelled to pretend that this three page double-sided document was only a passenger list. But since it included many prominent democrats who never had the slightest intention of catching that flight, such as legislators Martin Lee Chu-ming and Szeto Wah, it is hard to believe they expected anyone to believe this explanation. The existence of such a blacklist has long been suspected, since it is difficult to see how visa officials would otherwise know who should be denied entry. The only surprise about last week's tacit confirmation of its use was that it is so long. With an estimated 200 names, the list extend far beyond the Democratic Party's leadership to include close to half the party's active membership. Beijing's apologists are right to point out that such blacklists are not unusual. Most countries have one: although not usually of their own citizens. But such lists are normally kept secret: and only consulted in a back-room, out of public view. Yet last week border officials showed no such restraint. Journalists peered over their shoulders at the list of names, and some TV crews even managed to catch it on camera. Had China actually passed over a copy of the blacklist it would have been much too obvious that they were openly threatening everyone associated with the democratic camp. China has managed to convey the same message in a much more subtle manner by allowing the protesters to get as far as Beijing, knowing that they would be accompanied by a huge media entourage - and then permitting everyone to catch a glimpse of the list. The Foreign Ministry can deny its existence. But everyone in Hong Kong now knows there is an even more extensive blacklist than was previously suspected, and that any active involvement with the Democratic Party can lead to inclusion on it - so making it impossible to visit China. This may have the effect of discouraging popular participation in democratic politics for fear of the consequences of being added to the blacklist. China will certainly be happy if it does. For that would mean last week's stand-off in Beijing has worked to the mainland leadership's benefit.