The Federal Communications Commission defended itself against challenges to the legitimacy and constitutionality of the net neutrality rules it put in place in late 2010 in a 79-page page brief filed with the U.S. Court of Appeals for the D.C. Circuit. The FCC's brief is a response to challenges by MetroPCS and Verizon who claim, among other things, that the FCC doesn't have the authority to enforce the rules, that the rules violate their First Amendment rights, is arbitrary and capricious and an abuse of its discretion.
The FCC countered that "Internet access providers do not engage in speech" and that "they transport the speech of others, as a messenger delivers documents containing speech. Unlike cable systems, newspapers, and other curated media, broadband providers do not exercise editorial discretion. Verizon has defended itself from lawsuits on that very ground. If the First Amendment applies at all, the Open Internet Rules are narrowly tailored to serve important government interests."
The Citizens United ruling by the Supreme Court could come into play on that front – that ruling basically established that, like people, corporations do have the right to free speech.
The FCC also argued that net neutrality rules are needed to stop broadband providers from "interfering with their customers' ability to use Internet services" and that the commission does have the authority to adopt the rules.
We will have to wait and see how this plays out. Obviously if MetroPCS and Verizon are successful, it could unravel the groundwork the FCC has already laid down to keep ISPs from manipulating traffic and services that either compete with their own services or that they just don't like…