IT IS ILLEGAL for a Original Equipment Manufacturer (OEM) or their service representative to require you to use or purchase a particular brand of supplies just as it is illegal for your car dealer to require only original parts to fix your car. An OEM cannot void your warranty unless they can conclusively prove that the other brand of supplies will damage your machine. To enforce a policy such as this is in direct violation of the Sherman & Clayton Antitrust Acts.

IBM VS. THE UNITED STATES, a case brought before the U.S. Supreme court, set the precedent. The high court ruled that companies which engage in the practice of requiring or intimidating their customers into purchasing supplies or replacement parts from them exclusively creates a tying agreement, which was found to be in violation of the Antitrust Laws.