If you maintain a blacklist of journalists you want to keep out on sensitive dates, you should at least make sure it's up to date and accurate.
Putting aside the morality of an accountable government even keeping such a list, it's embarrassing and wholly counterproductive if you kick out the wrong person. You can be sure the news organisation that employs him will kick up a big fuss and that it will become instant headline news reflecting badly on your government.
That is exactly what happened when Macau's immigration authorities inexplicably denied entry to South China Morning Post photographer Felix Wong Chi-keung to cover Labour Day events. No official explanation was given. However, the Post's reporter had no trouble getting in or out.
Felix has had problems with Macau authorities before, but it all looked arbitrary. He was twice barred from entering Macau in 2009 when he was assigned to cover security legislation and the trial of Ao Man-long, Macau's disgraced former secretary for transport and public works. But he has since been allowed to enter Macau on four other occasions - twice on photographic assignments and twice on private visits.
Any self-respecting and efficient government should at least offer a plausible explanation of how it decides whom to reject or welcome. Macau has not done so.
I have worked with Felix for as long as I have been at the Post, and I have never heard a controversial political opinion from him. So unless he is a closet spy or activist, of which I have seen absolutely no sign, I can only conclude that the authorities in Macau keep a highly inaccurate list of unwelcome people and that its immigration office is totally inefficient.