SAN FRANCISCO The producers behind the YouTube channel "ZombieGoBoom" are suing Google Inc. claiming that recent changes in the way ads are placed on streaming videos have unfairly affected them and others who rely on YouTube ad revenues for income.

Google made adjustments to address advertiser concerns in March after The Wall Street Journal reported that YouTube was placing ads on objectionable content such as videos supporting neo-Nazi causes and ISIS. The changes have been dubbed the "Adpocalypse" by some YouTube content producers. James Sweet and Chuck Mere, the Fayetteville, Arkansas-based filmmakers behind the ZombieGoBoom channel, claim in a federal lawsuit filed Thursday that the changes caused their monthly YouTube-based income to plummet. Their series, which they describe as "a live action zombie series that is essentially a combination of 'Mythbusters' and 'The Walking Dead,'" has seen ad revenues drop from about $300 to $500 per day to $20 to $40 per day since March 27, according to the complaint.

In June, YouTube VP of product management, Ariel Bardin, acknowledged that the roll out of the changes had impacted content creators and that the company needed to work how it communicated changes to its advertising polices. "We know that revenue fluctuations have been unsettling and want to reassure you that we're working closely with our advertising partners to make sure that YouTube continues to be a great place for creators to earn money," wrote Bardin, in a June 1 post to the company's blog.

The lawsuit, filed in U.S. District Court for the Northern District of California by lawyer Todd Friedman of Woodland Hills, claims people who rely on YouTube income have been affected by "the draconian and reckless application of its demonetization algorithms."

"The result were thousands of content providers suddenly having their livelihoods jeopardized with the flick of a switch by YouTube, without explanation, notice or recourse," Friedman wrote.

The suit seeks to certify a national class of YouTube content producers. It brings claims under California's Unfair Competition Law as well as common law claims of breach of contract and breach of duty of good faith and fair dealing. A Google press representative passed along the following statement: "We have always worked hard to provide creators with the opportunity to earn revenue on our platform."