After Michael Bay and his film crew were allegedly threatened by gangsters in Hong Kong who demanded "protection money" from them, there were reports of Hongkongers apologising online to the Hollywood director on behalf of the SAR. (These were probably not the same people who cheered the tragic death of a mainland Hong Kong University student in a traffic accident some weeks before - but the dramatically different responses to the two episodes speak volumes about mainland-Hong Kong ties.)
It is intriguing that despite Hong Kong being one of the most policed territories in the world, the underworld looms large in both the public consciousness and in reality. No numbers are forthcoming, but I'm sure that for many, especially those running small businesses, protection money is a fact of life. That wouldn't be so different to how things worked in China of old during times of lawlessness or in remote areas beyond the reach of the law.
Itinerant merchants transporting goods, armed escorts delivering valuables or anyone who appeared "flashy" could be waylaid by armed robbers, some of whom were members of veritable armies of bandits, numbering several thousand, ensconced in mountain citadels. Those who were assailed might put up a fight, but often they would give the robbers either money or a portion of their goods in return for safe passage - payments that would already have been factored in as part of their "transport costs".