Price controls - triangular interventions - occur when an intervener (generally government) either compels a pair of people to make an exchange or prohibits them from making an exchange. Although ludicrous, price controls are instituted because a product appears to be in short supply, e.g. oil - while price controls create artificial shortages of the product. The conservation movement ties in with the attack on comfort and consumption and humans in general.
Lecture 4 of 4 from Austrian Economics: An Introduction, presented at New York Polytechnic University in 1972.