More than 10,000 people in Britain were targeted online in the past five years by hostile states, including China, who are seeking to recruit high-level officials through networking sites as spies. Government officials and researchers with access to classified or commercially sensitive technology are at greatest risk from adversaries using fake profiles on sites such as LinkedIn, a new campaign launched this week found. Unwitting potential targets are encouraged to link with foreign agents after being lured by so-called unique business opportunities or paid speaking roles at prestigious conferences, the UK security agency the Centre for the Protection of National Infrastructure said. The 'Think before you Link' campaign is to warn 450,000 civil servants and private sector researchers about the danger of states manipulating networking sites for their own ends, the <em>Financial Times</em> said. Foreign recruiters would then entice people to face-to-face meetings in which they could be bribed or blackmailed. Officials declined to give details of countries or social media platforms, but China is known to use LinkedIn to snare targets. A video used to publicise the campaign features a male East Asian spy masquerading as a female recruiter. China has history of using social media sites to secure classified information. Dickson Yeo, a Singaporean recruit for Chinese intelligence, spied on the US for four years after being given the task of spotting senior officials with access to important information. The academic set up a fake political consultancy and trawled through social networking sites to find potential targets. He was jailed for 14 months before being returned to Singapore last year. Ken McCallum, director general of security agency MI5 that oversees the work of CPNI, said the abuse of social networking sites was on an “industrial scale”.