What is antitrust & why it is so important. Federal and state antitrust laws are designed to protect competition, and the opportunity of competitors to engage in business free of artificial restrictions on competition. Such restrictions include price fixing agreements, group boycotts, “tying” arrangements, and market allocation arrangements. Antitrust laws also make it illegal to operate a monopoly and abuse the power of one who has a monopolistic market position. Antitrust laws are enforced by the U.S. Department of Justice, the Federal Trade Commission, and similar state agencies and state Attorneys General.