In the United States, the Federal Communications Commission attempted to introduce similar restrictions on cable broadcasts of specific sporting events and recent films as to not cannibalize broadcast TV. In 1977, these restrictions were deemed to be invalid when a federal district court ruled that the FCC did not have the authority to make such decisions in a consolidated case, also noting that the constitutional basis for such a law had not been proven. No such laws have been passed since. Since then, sports have been a lucrative source of revenue in the U.S. pay television industry, including mainstream networks such as ESPN, as well as channels devoted to specific sports, leagues, and college sports conferences. These networks receive revenue from both advertising and carriage fees charged to television providers (and passed onto consumers as part of the cost of service), and can provide an outlet for expanded coverage of "niche" events with dedicated audiences.