Philip Bartlett, chairman of the Maine Public Utilities Commission, speaks with reporters at the University of Southern Maine in Portland in 2019.

Internet service providers are challenging Maine’s new “opt-in” web privacy law, one of the strictest in the nation, in federal court in Bangor.

The complaint, filed Friday, claims that Maine’s law violates the free speech clause of the Constitution. Four industry associations are asking U.S. District Judge Lance Walker to issue an injunction to keep the law from taking effect July 1.

The law prohibits internet service providers from using, disclosing, selling or permitting access to a customer’s personal information unless a customer gives the provider permission to do so.

It also requires providers to take reasonable measures to protect customers’ personal information from unauthorized use, disclosure, sale or access. In addition, it prohibits providers from refusing to serve customers or charge customers who do not consent to their personal information being shared.

The law also would limit internet service providers from advertising and marketing non-communications-related services to their customers, and from offering price discounts, rewards in loyalty programs and other cost-saving benefits, according to the lawsuit.

“The statute’s speech restrictions are also too vague to comply with due process because they force ISPs to guess at the boundaries of those restrictions,” the complaint said. “The statute’s amorphous, broad, and open-ended restrictions will therefore chill ISPs’ protected First Amendment speech.”

The complaint also claims that Maine’s law is preempted by federal law and regulations set by the Federal Trade Commission and the Federal Communications Commission.

The internet privacy bill, sponsored by Sen. Shenna Bellows, D-Manchester, was designed to reinstate rules implemented by President Barack Obama’s administration but repealed in 2017 by a Republican-led Congress. The ACLU of Maine, Attorney General Aaron Frey and GWI, a Biddeford-based internet service provider, supported the bill. It was opposed by national trade groups for the wireless communications and broadband industries, including at least one that is a plaintiff in the lawsuit. The Maine State Chamber of Commerce also opposed the bill.

The bill was supported unanimously in the Maine Senate and by a vote of 96 to 45 in the House. Gov. Janet Mills signed it into law June 6.

The plaintiffs in the lawsuit are: ACA Connects — America’s Communications Association; CTIA — the Wireless Association; NCTA — the Internet & Television Association; and USTelecom — the Broadband Association.

In a joint statement issued Wednesday the organizations said that “protecting consumer privacy is a vital national goal. Consumers expect – and deserve – the same meaningful privacy protections across the internet. Broadband providers are united in support of a comprehensive national privacy framework that puts consumers first and applies to all companies, including all those operating online, in a uniform and technology-neutral manner.”

It also said that Maine’s law has “serious substantive flaws.”

“Maine’s approach of regulating the collection and use of data by internet service providers only, and not the practices of other companies, including the largest internet companies, data brokers, and others that collect, use, and monetize even more data than ISPs, leaves a gaping hole in the law, is unconstitutional, preempted by federal law, and should be struck down by the courts,” the groups said.

The defendants in the lawsuit are Frey and the Maine Public Utilities Commission’s three commissioners: Chairman Phil Bartlett, R. Bruce Williamson and Randall Davis.

Frey, who supported Bellows’ bill, said Wednesday afternoon that his office “will vigorously defend the law the Legislature passed to protect the privacy of online consumer information.”

“The law provides an important safeguard against the increasing exploitation of Mainers’ personal information by companies who employed coercive tactics to obtain their consent,” he said. “If the telecom industry wishes to fight to preserve their right to exploit consumers’ personal data, which includes their physical location, the websites they visit, and the content of their communications, this is a fight I am willing to have.”