A call to arms has been issued to everyone in Hong Kong to join a “vast and borderless” war against scammers. The number of swindles has surged since the start of the pandemic, more than doubling in 2020 from the previous year. Cases have been rising since then, with police logging 19,444 scams in the first nine months of this year alone. Victims are from all walks of life, with students, pensioners and professionals among those defrauded. Some have lost millions to con artists who threaten, confuse or falsely offer jobs and ways to make quick money. The online crime problem has grown even as the overall crime rate remains largely stable, meaning that scammers have become a bigger headache for police than thieves or violent criminals. Hong Kong is not alone in facing a global threat enabled by rising internet use and accelerated by Covid-19 fears and restrictions that have sent people online for work, shopping or companionship. Scammers find plenty of victims among those who rely on such technology. The biggest challenge is that online rackets are “cross-boundary and anonymous”, according to Chief Superintendent Kelly Cheng Lai-ki. The head of the force’s cybersecurity and technology crime bureau said officers had made progress with new squads, improved training and expanded facilities including a digital forensics complex set to go into operation next year. Discussions are also under way with banks and the Communications Authority on ways to flag suspicious phone calls. A new police “Scameter” website in place since September has already stopped scammers from getting away with more than HK$400 million. Email swindles have decreased thanks to new V@nguard software jointly developed with the University of Hong Kong to detect “phishing” rackets. While the force has arrested thousands on fraud charges this year alone, the cybercrime detection rate is still lower than the figure for overall crime. Efforts to alert potential victims and block swindlers should be applauded, but enforcement and online tools are no match against an enemy reliant on complacency and inattention. We must all do more to defend ourselves online to help defeat the scammers.