Mainland and Hong Kong police have smashed a ring of computer hackers with the arrest of six suspects in the mainland.
The group was reportedly involved in a scheme to blackmail Hong Kong securities companies for 460,000 yuan (HK$562,000).
From February to June, Hong Kong police received reports from 16 firms in gold, silver and securities trading that their websites had been attacked by hackers. One firm was the Chinese Gold & Silver Exchange Society.
Fifteen of the companies were told to remit amounts ranging from 30,000 to 100,000 yuan into bank accounts in Hunan, Hubei, Shanghai and other areas, or face further website attacks and a blocking of their businesses.
It was suggested Hong Kong's financial stability would also be harmed.
Four of them remitted a total of 290,000 yuan to the designated accounts from February to April, with one company forced to pay up 26 times.
In May and June, the Ministry of Public Security arranged for Hong Kong police to meet their Hunan counterparts to discuss the case.
On June 20, Hunan police began rounding up the six suspects in Hunan, Hubei, Shanghai and other places.
Investigations show the gang organized internet traffic to attack the targeted SAR companies before using instant messaging to blackmail them.
Industry sources said the victim firms were likely to be connected to London and local gold trading, with extensive business in the mainland.
One source alleged some of the companies may also have been involved in illegal activities, which explains why they succumbed to blackmail.
"Blackmailers are usually interested in large-sized brokerages," a source said. "They pay close attention to those with high trading volumes."
Information technology lawmaker Samson Tam Wai-ho said internet crime is a global trend. He said these cases suggest many companies in Hong Kong may not know that existing laws can protect them from internet criminals.
Tam said many small and medium enterprises may be willing to pay small sums when faced with internet blackmail to avoid having their business blocked.
Tam urged corporations to look for better security backup and facilities, and to notify police once they are threatened with blackmail.
A Hong Kong police spokesman urged companies to step forward if they have received similar blackmail threats.
Police will continue cooperating with other regions to fight cross-border internet crime.