Barely an hour after California Gov. Jerry Brown signed what's widely believed to be the toughest net neutrality law ever enacted in the US, the US DOJ announced that it would sue California to invalidate the new law, setting up yet another showdown between the federal government and the largest state in the union.

According to the Washington Post, California has become the largest state to adopt its own rules requiring Internet providers like AT&T, Comcast and Verizon to treat all web traffic equally. State lawmakers wrote their law after the FCC scrapped nationwide protections last year, citing the regulatory burdens they had caused for the telecom industry. The lawsuit opens yet another legal showdown between Brown and Attorney General Jeff Sessions. Recently, a federal judge threw out most of the DOJ's challenge to California's sanctuary state laws.

The law will pit massive ISPs like Comcast and Verizon against smaller Internet companies like Etsy and streaming services like Vimeo.

As the DOJ explains in its press release, federal laws explicitly state that the Internet should not be regulated as if it were a utility. However, this assumption undergirds the argument for enforcing net neutrality by law. For years, net neutrality was merely a principle to which ISPs adhered. It wasn't until the Obama Administration-era FCC imposed certain restrictions on ISPs that net neutrality were enshrined into law.

And as Sessions pointed out in a statement, states do not have the right to regulate interstate commerce.

"Under the Constitution, states do not regulate interstate commerce - the federal government does. The Justice Department should not have to spend valuable time and resources to file this suit today, but we have a duty to defend the prerogatives of the federal government and protect our Constitutional order," Sessions said in a statement. [...] "Not only is California’s Internet regulation law illegal, it also hurts consumers," Pai said in a statement. "The law prohibits many free-data plans, which allow consumers to stream video, music, and the like exempt from any data limits. They have proven enormously popular in the marketplace, especially among lower-income Americans. But notwithstanding the consumer benefits, this state law bans them."

FCC Chairman Ajit Pai, who received death threats last year after the FCC undid the Obama-era regulations, said in a statement that the California law isn't just illegal, but also hurts consumers.

"I’m pleased the Department of Justice has filed this suit. The Internet is inherently an interstate information service. As such, only the federal government can set policy in this area. And the U.S. Court of Appeals for the Eighth Circuit recently reaffirmed that state regulation of information services is preempted by federal law." "Not only is California’s Internet regulation law illegal, it also hurts consumers. The law prohibits many free-data plans, which allow consumers to stream video, music, and the like exempt from any data limits. They have proven enormously popular in the marketplace, especially among lower-income Americans. But notwithstanding the consumer benefits, this state law bans them."

And with other states stepping up to pass net neutrality laws of their own, the DOJ has every incentive to take this lawsuit all the way to the Supreme Court (where hopefully, assuming Brett Kavanaugh is confirmed, the court's conservative majority will rule in the DOJ's favor).

In this case, the future of Internet regulation is at stake in a political war that’s pit telecom providers such as Verizon against tech companies, especially smaller ones such as the crafts site Etsy and the streaming service Vimeo. With other states considering net neutrality laws of their own, the DOJ "may want to try to take [California] to the Supreme Court if it goes that far," said Carl Tobias, a law professor at the University of Richmond.

The first salvos in what looks to be a multiyear legal saga were fired just weeks before the all-important midterm elections (though it's hard to imagine that this will do much galvanize either side's base, as most consumers have no idea what net neutrality is, exactly).

Emboldened by online activists, liberal organizers and tech start-ups, California lawmakers set about crafting their own net neutrality rules earlier this year. The proposal that the legislature adopted in September - which the governor’s office allowed to become law Sunday - prohibits Internet providers from blocking access to sites and services, slowing down web connections or charging companies for faster delivery of their movies, music or other content. Smaller web firms, in particular, worry that they do not have the resources to pay telecom giants to make sure their content is seen. The law also bans carriers from exempting apps from counting toward consumers’ data allowances each month if doing so might harm companies, especially start-ups. California’s law is even tougher than the approach adopted in 2015 while President Obama was in office - which was scrapped after Republicans took over leadership of the FCC two years later. To Ajit Pai, the FCC’s current Republican chairman, such net neutrality protections proved heavy handed and had slowed the telecom industry’s investment in improving their broadband networks nationwide. "I think ultimately it’s going to mean better, faster, cheaper Internet access and more competition," Pai told the Post as the repeal took effect in June.

The California Assembly and Senate passed the law over the summer, ignoring the objections of telecom lobbyists who have largely favored the DOJ's less-restrictive approach to the Obama-era policies. While California's law is certainly ambitious and mirrors the state's efforts to impose restrictive data privacy laws earlier this year, should the DOJ succeed with its case (an outcome that will almost certainly involve a SCOTUS ruling), it will settle the matter of net neutrality for a generation.