In 2003, the U.S. government created a "Do Not Call Registry" and forbade marketing firms from calling people who placed their names on this list. Today, an increasing number of companies are sending mail solicitations to individuals inviting them to send back an enclosed postcard for more information about the firms' products. What these solicitations fail to mention is that they are worded in such a way that someone who returns the postcard gives up protection from telephone solicitations, even if they are on the government's "Do Not Call Registry." In what type of behavior are these companies engaging? Explain your answer.