One of the most serious threats to a modern country’s trade, industry and long-term economic development is cyber espionage and insiders. The activities are directed against high-technological industries and companies with advanced basic research. The defence and telecoms sectors are of particular interest, just as biotechnics, medical and material technology. Behind this kind of espionage there may be individual states and security services as well as competing companies. One trend is that criminal players are getting involved both as thieves and fences of information. Computerisation and the development of the Internet drastically increase the possibility of procuring sensitive information through illegal means. This can be done in different ways. In the paper the convergence between industrial-and cyber espionage are discussed. A number of examples are provided of different kinds of espionage as well as some of the methods that is used to collect information over the Internet – such as signals intelligence, monitoring of traffic, penetration and overtaking of computers with the aid of trojans. Examples are given on succesful cybertheft operations such as the operation Buckshot Yankee and the Chinese Ghostnet. The paper ends with a discussion on how to improve information security in organisations in order to reduce the risks for illegitimate information drainage.