What is it, one wonders, about Secretary for Security Chris Tang and the Hong Kong Journalists Association (HKJA)? Tang, after all, has a lot on his plate. He is responsible for repelling every threat to peace, order and national security in Hong Kong. The latter, we are often told, needs constant alertness and attention. Yet it seems Tang is never too busy to have a go at the HKJA. The HKJA is a small voluntary body aiming to serve and protect the interests of people working in journalism. It does the usual things: seminars, workshops, occasional dinners and the odd press release on relevant …