Both Hong Kong and Macau are constitutionally required to pass national security legislation under Article 23 of each's Basic Law. But while Macau's legislature approved such a law without a hitch yesterday, our government's attempt to introduce similar legislation in 2003 failed because of concerns over the tightness of the provisions and enforcement. If the experience of this newspaper's photographer, Felix Wong Chi-keung, is any guide, Macau residents could have cause to regret their lack of questioning. On the day the bill was passed, their immigration officers for the second time in six days denied him entry. Wong is not a troublemaker. As was the case last Thursday, he was trying to enter Macau to carry out his professional duties. But again, he was barred as he presented his identity card at immigration, and no explanation was given, other than the refusal was under internal security regulations. To prove matters are amiss, he immediately went to the mainland and had no problem entering Shenzhen and returning to Hong Kong. Why Wong can freely visit other parts of China, while being barred from Macau, deepens the mystery. Authorities have not responded to our questions as to the anomaly. Freedom of speech and movement, and a free press are enshrined in Macau's Basic Law. That no answers have been forthcoming is disturbing. We believe our photographer is the first journalist on an assignment to Macau to have been denied entry. Pan-democratic legislators from Hong Kong and other people deemed to be activists are among those who are routinely barred. The incidence of such cases would seem to have been increasing of late; 20 lawmakers were not allowed in during December. These incidents raise doubts that Macau will implement the security law in a fair and reasonable manner. If it does otherwise, as would seem to be the case with our photographer, its image will suffer. The ongoing corruption trial of disgraced former transport and public works minister Ao Man-lung has already taken its toll. For its own sake, our questions must be answered.