Final answer:
The statement regarding U.S. cities building competing, municipally owned cable systems is true. This can be framed as an aspect of municipal socialism where local governments take control of public utilities to compete with private giants and offer better services to residents.
Step-by-step explanation:
Some U.S. cities are indeed challenging privately owned cable giants by building competing, municipally owned cable systems, and the statement is true. The concept of public utilities holding a natural monopoly, especially in the context of essential services like water and electricity, is well-established. However, with the consolidation of media and telecommunication companies, as seen with the merger of Comcast and NBC Universal, there has been a significant push for alternatives, including municipal initiatives to expand into public ownership of utilities like cable systems. This transitions into what's often called 'municipal socialism,' where cities in the past, like those in Ohio, took control of utilities and public services to offer lower costs and more control over services to residents.