When it comes to industrial espionage, "one-hit wonders" — employees, such as Chelsea Manning or Reality Winner, who take valuable proprietary information to a competitor, the media or a foreign government — are just half of the equation. Companies also need to remember the threat of low-key spies on staff who may quietly provide their handlers with sensitive facts and figures over months, years and even decades. The damage these employees can inflict may rival or exceed the harm caused by a one-time loss. In April, Stratfor hosted a lunch meeting on insider threats for chief security officers attending the European conference of ASIS International in Rotterdam, Netherlands. I also spoke on the tradecraft used by those trying to recruit insiders to commit industrial espionage. The conference demonstrated the enduring interest in the topic, and for those who couldn't make it to Rotterdam, I offer this discussion.