As the case of prescription drugs suggests, however, there were problems with this approach. In part, it assumes that consumers do adequately under¬stand and judge products so that they can reasonably be expected to protect themselves. But consumers don't always understand products fully and they are not always free to choose not to purchase some things. Starting in the 1960s, a number of important legal cases shifted the burden from consumers to producers by allowing consumers to assume that products were safe for ordinary use. By bringing goods and services to the market, producers were implicitly promising that their products were safe under normal use. The ethi¬cal basis for this decision is the assumption that consumers would not give their consent to a purchase if they had reason to believe that they would be harmed by it when used in a normal way