The FCC voted last December to remove net neutrality protections including bans on throttling, blocking and paid prioritization. The new regulations went into effect in June, but a number of states have been working to get around them, despite the FCC's declaration that states can't enact rules that contradict its own. Some states have incentivized ISPs to abide by net neutrality by withholding government contracts from those that don't. Others, however, have passed their own net neutrality legislation.

Last month, California enacted a new law that largely restores the protections repealed by the FCC, a move that supporters have championed. But FCC Chairman Ajit Pai has called the law "illegal" and the state has since been sued by both the Department of Justice and industry groups representing companies like AT&T, Charter, Comcast and Verizon.

The FCC and DOJ urged the US Court of Appeals for the District of Columbia to deny the plaintiffs' petition for review. The court is set to hear arguments for the lawsuit in February.