Former Facebook security chief Alex Stamos warned that activist investors could start buying up Tesla shares -- and even attempt to wrest control of the company from Elon Musk -- if the electric car maker's stock doesn't start to turn around: It's down more than 62% so far this year.Activist investors buy up big stakes in public companies and then agitate for change -- sometimes in the board room. "If it continues to drop this hard, then you're going to end up with activist investors getting in, and those activist investors are going to push to get onto the board and then to put pressure on Musk -- or even to maybe kick Musk off as CEO," Stamos said of Tesla's big stock drop in an episode of the "Moderated Content" podcast that was published on Monday.If an activist does come along -- and so far, there's no indication of that happening -- they could finally "be the brake on Musk's behavior," Stamos said, pointing to his controversial reign as Twitter's chief so far. "That might be the thing that kind of slaps him in the face of whether or not its worth it to do this," Stamos said. Musk and a Tesla spokesperson did not respond to a request for comment from Insider ahead of publication. He last spoke out against rumbling of an activist investor trying to unseat a founder when some people were making noise that Mark Zuckerberg should be deposed from the top seat at Facebook in 2019. Stamos made the comments after Musk made a series of erratic statements on Twitter -- from calling for White House chief medical advisor Anthony Fauci to be prosecuted and mocking the LGBTQ+ community to insinuating Twitter's former security chief Yoel Roth has a permissive view of pedophilia. Stamos didn't return Insider's request for comment ahead of publication.Over the past week, Tesla shares have hit their lowest value since November 2020. Meanwhile, Musk sold more of his Tesla holdings to help fund his $44 billion Twitter purchase on Wednesday -- offloading nearly $40 billion worth of Tesla stock in the past 14 months. Tesla's stock was trading a little over $150 a share late Friday. On Wednesday, major Tesla shareholder Leo KoGuan called for a new CEO to takeover. KoGuan has amassed about 22.6 million Tesla shares as of September. "An executioner, Tim Cook-like is needed, not Elon," he tweeted. KoGuan said an executive like the Apple CEO, who's known as a quiet operations genius, would be a better fit, saying "Elon abandoned Tesla. "On Monday, Wedbush tech analyst Dan Ives said Tesla is a ripe target for activist investors, adding that the company is likely to face increased pressure from activist investors in 2023 to launch a stock buyback program, improve profit margins, or make "strategic moves." Ives has been critical of Musk's preoccupation with Twitter in the past. Though, the tech analyst said in a note on Thursday that he maintains his outperform rating on the stock due to his optimism around the future of the EV industry. "The market is speaking to the board," Klepper said of Tesla's recent stock drop. "It's simple as that."