In April of this year, the US Federal Bureau of Investigations (FBI) warned government contractors that their employees are being targeted on social media by foreign intelligence services, with the aim of recruiting individuals with US government security clearances.

The alert outlined four recent, real world examples of campaigns that were launched by foreign intelligence services in order to recruit US government contractors for espionage purposes. Campaigns of this kind have become increasingly common in recent years.

Read more: FBI warning: Foreign spies using social media to target government contractors