Interactive cable television systems take advantage of the ability of coaxial cables to transmit information in two directions. QUBE in Columbus, Ohio, and Project Ida in Canada use cable's interactive ability to provide a variety of services. QUBE allows electronic "town meetings" and provides access to stock quotes, newspaper headlines, encyclopedia listings, and electronic games. Using sensors, it can also provide home security. Among other services, Project Ida provides automatic meter reading and teleshopping to a thinly populated region. There are, however, dangers associated with interactive cable systems. Media corporations seek regulated monopolies as a way of maximizing profit, not customer service, and the use of interactive cable also opens up the possibility of violations of privacy through the improper collection or misuse of information about subscribers. Since these potential economic distortions and violations of privacy are directly related to lack of competition in providing these services, public policy should formulate regulations that encourage competition. (JL)