Electronic discovery (e-discovery) describes any process where electronic data is sought, secured, located, explored and retrieved with intented use as evidence in a civil or criminal case. Electronic discovery may be performed offline on an individual computer or in a computer network. A court may use actual hacking for specific criminal data retrieval orders, which is considered legal. Total destruction of digital data is extremely difficult, especially if the data is distributed on a network. Hard disk data cannot be completely deleted and can be retrieved with sophisticated data recovery tools, even after a user has attempted to remove the data. This allows law enforcement to track down criminal evidence.