During World War II, the United States strictly diverted its hijackings from the cartels.  After 1945, the market liberalism promoted by America led to a global ban on cartels, in which cartels in more and more countries and under certain circumstances are hindered. Outright cartels (when companies agree not to compete with each other) are the most serious violations of competition law. They hurt customers by raising prices and restricting supply, making goods and services completely unpackable for some buyers and unnecessarily expensive for others. As noted in the MOU, it is more likely that the ACCC will consider the conduct it is investigating to be serious cartel conduct if one or more of the following factors are true: the behaviour of the cartel may result in higher prices and reduced choice and quality. .