Cable giant Comcast started making its argument for buying up the second largest cable operator in the U.S., Time Warner Cable, this week. In part four of our series "Comcast's Competitors?" we'll look at net neutrality -- a recently troubling issue that Comcast says will be bolstered by its takeover of TWC.

Read Part One of "Comcast's Competitors?" DLS and Google Fiber

Read Part Two of "Comcast's Competitors?" Wireless Broadband

Read Part Three of "Comcast's Competitors?" Digital Divide

Besides a lengthy filing with the Federal Communications Commission, Comcast exec David L. Cohen wrote a blog post for the public explaining the company's reasoning for why its acquisition of TWC is good for the industry, and the nation. Besides arguing that there would be plenty of competition after the merger (read parts 1 and 2), Cohen wrote about extending net neutrality to TWC's territories. Let's take a closer look.

Expanding Net Neutrality

In the blog post, Cohen writes, "As another benefit for consumers, we'll extend network neutrality protection to millions more broadband customers through our commitment to the FCC's Open Internet rules.  Today, Comcast is the only company in America that is legally bound by the FCC's now vacated Open Internet rules.  We'll extend those protections to customers in TWC areas."

Comcast is the only company where net neutrality is still the same thing as it was before a federal appeals court struck down the FCC's ability to enforce its Open Internet rules earlier this year.

But, as we mentioned in part 3, on the question of Comcast's Internet Essentials plan for low-income families, this is not simply out of the goodness of the company's heart.

Both the Internet Essentials program, and abiding by the FCC's Open Internet rules, circa 2010, is required by law.

Specifically, the FCC required that Comcast abide by the FCC's net neutrality-friendly Open Internet rules as part of the deal for buying NBCUniversal, an entertainment/news content company. And as the Daily Dot mentioned, Comcast hasn't always been friendly to net neutrality, fighting the FCC's jurisdiction over Comcast's broadband service and ultimately winning, temporarily, in 2010.

So it's true that gobbling up TWC will extend net neutrality protection to millions more Americans.

But What Happens in Five Years?

Comcast is committed (by law) to net neutrality. That is, until 2018, when the terms of the NBCUniversal merger agreement are null.

It's hard to see five years into the future, especially as the FCC is still getting its ducks in a row after losing its ability to enforce net neutrality this year. But it appears that FCC Chairman Tom Wheeler's new regulating scheme won't be as robust or strong as the previous Open Internet rules.

By then, if nothing has been done to re-enforce the Open Internet, other than Wheeler's proposed case-by-case basis, Comcast will already have an outsized influence on how new decisions get made. As 50 or so public interest groups put it in an open letter to the FCC this week, the merger "would give one company enormous power over our nation's media and communications infrastructure," and would "position Comcast as our communications gatekeeper, giving it the power to dictate the future of numerous industries across the Internet, television, and telecommunications landscape."

Read on to Part 5, where we look at the contradictory and perplexing elements in Comcast's argument for buying TWC.

Read Part One of "Comcast's Competitors?" DLS and Google Fiber

Read Part Two of "Comcast's Competitors?" Wireless Broadband

Read Part Three of "Comcast's Competitors?" Digital Divide