Sentences are partly cited from "apple daily(蘋果日報)"
http://tw.nextmedia.com/rnews/article/SecID/103/art_id/53483/IssueID/20110722/page/1
陸男在香港金紫荊廣場燒五星旗被捕 (蘋果日報)
According to the mass media in Hong Kong, a man from Mainland China tore and burnt the national flag of People's Republic of China at The Golden Bauhinia Square in Wanchai, Hong Kong.
At the same time, the man shouted "Subvert Chinese communist party!". He was arrested for violating an ordinance on the flag.
Though he may have thought Hong Kong is better place to express his anti-Chinese communist party thoughts, Beijing government monitors anti-Chinese communist party activists or threatens Hong Kongers with water supply or electricity supply (These are rumors I've heard from a tour conductor living in Hong Kong)