Data theft

Data theft is a growing phenomenon primarily caused by system administrators and office workers with access to technology such as database servers, desktop computers and a growing list of hand-held devices capable of storing digital information, such as USB flash drives, iPods and even digital cameras. Since employees often spend a considerable amount of time developing contacts and confidential and copyrighted information for the company they work for, they may feel they have some right to the information and are inclined to copy and/or delete part of it when they leave the company, or misuse it while they are still in employment. Alternatively, an employee may choose to deliberately abuse trusted access to information for the purpose of exposing misconduct by the employer; From the perspective of the society such an act of whistleblowing can be seen as positive and is in certain situations protected by law in some jurisdictions, such as the USA.

While most organizations have implemented firewalls and intrusion-detection systems, very few take into account the threat from the average employee that copies proprietary data for personal gain or use by another company. A common scenario is where a sales person makes a copy of the contact database for use in their next job. Typically, this is a clear violation of their terms of employment.

Notable acts of data theft by a self-proclaimed whistleblower have been done by: Chelsea Manning, Edward Snowden and Hervé Falciani.

...
Wikipedia