California Gov. Jerry Brown signed a tough new net neutrality bill into law Sunday, but the Justice Department promptly filed suit to keep the protections from taking effect.

Why it matters: The issue seems destined for the courts to decide between challenges to the FCC's moves as well as the California law. In rolling back protections last year, the FCC included language designed to preempt new state laws.

The details: In its suit, the Justice Department also maintains that California's law is an attempt to regulate interstate commerce, which is under federal purview.

What they're saying:

Attorney General Jeff Sessions : "Once again the California legislature has enacted an extreme and illegal state law attempting to frustrate federal policy. 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."

: "Once again the California legislature has enacted an extreme and illegal state law attempting to frustrate federal policy. 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." FCC Chairman Ajit Pai: "The law prohibits many free-data plans, which allow consumers to stream video, music, and the like exempt from any data limits," 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," Pai said in a statement. California Attorney General Xavier Becerra: "A handful of powerful companies should not dictate the sources for the information we seek or the speed at which our websites load. We remain committed to ensuring that our internet can continue to represent freedom and opportunity, innovation and fairness."

"A handful of powerful companies should not dictate the sources for the information we seek or the speed at which our websites load. We remain committed to ensuring that our internet can continue to represent freedom and opportunity, innovation and fairness." Former FCC adviser Gigi Sohn: "California's net neutrality bill is now the model for all future state and federal legislation. It completely reinstates the 2015 Open Internet Order, including protections for interconnection and against anticompetitive and anti-consumer zero rating practices. This is what Internet users across the political spectrum have said they want by overwhelming majorities."

Our take: