Supporters of the rules say they preserve competition and consumer choice, but opponents argue they are an unnecessary burden on businesses and amount to government control of the Internet.
The Free Press suit alleged that the rules arbitrarily provided less protection for wireless Internet access, such as through smartphones, than traditional wired Internet access.
But the FCC is still fighting another front in the war to defend its rules. Verizon is suing to have the rules thrown out altogether, arguing the FCC stepped beyond its authority and enacted the rules without sufficient evidence of a problem.
Verizon filed a brief in federal court on Monday explaining its case against the regulations.