According to professor Darius Rejali, although dictatorships may have used tortured "more, and more indiscriminately", it was modern democracies, "the United States, Britain, and France" who "pioneered and exported techniques that have become the lingua franca of modern torture: methods that leave no marks." The practice of torture used as the oppression against political opponents or could be a part of a criminal investigation or interrogation techniques in order to obtain the desired information and keep law enforcement empowered over everyday citizens.