Hagens Berman has filed a national class-action lawsuit against Google (NASDAQ:GOOG), claiming the company unlawfully denies payments to thousands of website owners and operators who place ads on their sites sold through Google AdWords. The lawsuit, filed in the U.S. District Court for the Northern District of California, alleges that Google abruptly cancels website owners’ AdSense accounts, often without explanation shortly before payments are due, and refuses to pay for the ads that ran prior to the cancelation.

According to the suit, Google’s popular AdSense program translates annually to billions of dollars payable to website operators that host its ads via AdSense. Google’s AdSense advertising program induces website operators to host space for ads on their websites. Each time a visitor to the website interacts with the ad, the ad publisher who hosts the ad accrues earnings.

The complaint claims that the contracts and terms of service Google requires web publishers to sign are unconscionably one-sided, giving Google free reign to embark on what the suit claims are actions devoid of good faith or fair dealing.

The complaint also states, “Given Google’s contractual terms purportedly permitting it to withhold payment to publishers with disabled accounts, and in light of the experience of the plaintiff in seeing this policy actually effected, the total of earned funds that Google has refused to pay its AdSense publishers could be enormous.”

The lawsuit claims Google is in violation of contracts with users and in violation of the implied covenant of good faith and fair dealing, unjust enrichment, and violation of the California Unfair Competition Law.

One of the named plaintiffs, Free Range Content Inc., is a California corporation that was an AdSense publisher. At the end of Feb. 2014, Google issued a report setting forth Free Range Content's estimated earnings for the covered period. Then on March 4, 2014—two days before a scheduled Mar. 6, 2014 call with an AdSense representative was slated to occur—the plaintiff received word from the AdSense program that Google had disabled its account and withheld its earnings.

The lawsuit seeks damages for all U.S. Google AdSense publishers whose AdSense account was disabled or terminated, and whose last AdSense program payment was withheld permanently by Google.