California Governor Gavin Newsom is signing into law three bills that target the misuse of video, audio, and images created by artificial intelligence in a sweeping effort to crack down on election deepfakes.

Newsom had vowed to pass the legislation after billionaire tech CEO Elon Musk recirculated a deepfake video on his platform, X, in July featuring altered footage of Vice President and Democratic presidential nominee Kamala Harris.

The governor signed the bills during a fireside chat with Salesforce (CRM) CEO Marc Benioff at the annual Dreamforce conference in San Francisco on Tuesday.

Assembly Bill 2355 will require political advertisements to disclose whether they used generative AI to create or alter materials appearing in the ad. AB 2655 will hold large online platforms, such as Meta (META), liable for failing to remove or label deceptive election content within 72 hours of receiving a report by a user.

And AB 2839 prohibits individuals from creating or publishing deceptive content about candidates and election workers, made with AI, in the 120 before and 60 days after an election. The measure also allows a judge to order the content to be removed and issue a fine. The measure contains an urgency clause - taking effect immediately.

The fake Harris audio shared by Musk reached nearly 140 million views over the summer. In the deepfake, Harris's voice is altered to say, “I, Kamala Harris, am your Democrat candidate for president because Joe Biden finally exposed his senility,” adding that she was chosen “because I am the ultimate diversity hire” as “both a woman and a person of color.”

The video featured edited clips from past appearances by the vice president, but used an AI-generated voice. The YouTuber who originally posted the video disclosed that it was a parody. But Musk did not label the content as misleading, instead writing, "This is amazing." The post was an apparent violation of X's rules.

At the time, Newsom clapped back at Musk, posting on X, "Manipulating a voice in an 'ad' like this one should be illegal. I'll be signing a bill in a matter of weeks to make sure it is."

California has taken the lead on regulating AI by introducing a wave of legislation this year. Despite fears of overregulating the emerging technology, analysts view the new laws as a move in the right direction.

"I think it'll be a positive and will also make people more comfortable advertising on those platforms," Harvest Portfolio Management chief investment officer Paul Meeks told Yahoo Finance.