The newspaper industry is upping its tactics in the fight against ad-blockers.

The Newspaper Association of America, the industry association representing 2,000 newspapers (including the Washington Post), filed a federal complaint against the ad-blocking industry on Thursday, alleging that software companies which enable users to block ads are misleading the public.

The complaint asks the U.S. Federal Trade Commission, the government agency that oversees trade practices, to investigate ad blockers that offer “paid whitelisting,” – a service which charges advertisers to bypass ad-blocking software – along with services that substitute ad blockers’ own advertising for blocked ads or get around publishers’ subscription pages.

The NAA complaint comes at a moment when the newspaper industry continues to struggle with dramatic changes that have eroded its business. Advertising revenues have dropped from roughly $50 billion a decade ago to less than half of that today, according to the NAA. Revenues from print advertising continue to slip as readers consume more news online, and digital advertising brings in far less revenue than print.

Publishers increasingly feel they cannot afford to lose revenue from digital ads. They believe the industry’s future is dependent digital advertising – particularly the practice of showing tiny ads on smartphones, where the public is spending a growing share of its reading time.

But consumers often find those smartphone ads to be intrusive and pesky. Today users are blocking 11.7 percent of all ads, according to a recent survey by the ad-blocking company and Wells Fargo. The rise of ad-blockers is also tied to a 2015 decision by Apple to allow ad-blockers on iPhones and other company devices.

In recent months, the New York Times, the Wall Street Journal and The Washington Post have experimented with messages that gently ask readers to turn off ad-blockers -- or to consider subscribing. The FTC complaint demonstrates a growing willingness by publishers, who in the past have minimized the issue, to be more aggressive.

The U.S. Federal Trade Commission said it had no comment.

Ben Williams, head of operations and communications for popular ad-blocking software AdBlock Plus, owned by Eyeo GmbH - one of the companies mentioned in the NAA suit – said in an emailed statement that the NAA had misconstrued the services the company offers. The “only part of [NAA’s allegations] that resembles reality is the part about ad blocking being a statement of consumer dissatisfaction with an ad industry that has spied on them, deceived them and, most of all, annoyed them with intrusive ads for years.”

William’s said the company only white-listed ads that adhered to specific criteria, including size requirements and not disrupting the reading experience. He disputed the allegation that Ad Block Plus offered a pay-to-play system where users weren’t told that ads they had paid to block were being let in for a fee. Users, he said, could block all ads if they chose to do so.

Online advertising is part of the trade-off that defines much of the Web's economy. Much of what users do online is offered for "free" -- e-mail, social networks, web search -- only because companies can track the behavior of consumers and send them targeted ads.

Advocates of ad blockers say that the ads crowding websites these days are irritating, invasive and sometimes unsafe. Ads can slow downloading time. They sometimes take over entire screens, preventing users from seeing the content they actually want to read. Meanwhile, "malvertising" attacks have put malware into people's computers and devices by hiding in legitimate advertising.