At least they’re picking on people their own size.

Earlier this week, Elon Musk took a swipe at Mark Zuckerberg’s understanding of artificial intelligence, calling it “limited.” The Tesla and Space X CEO tweeted the statement in response to Zuckerberg’s recent chat with users on Facebook live, where the Facebook CEO called Musk’s fear of artificial intelligence “really negative and in some ways…pretty irresponsible.”

This isn’t the first time that high-ranking executives have publicly lashed out at each other. Here are 7 times executives talked major trash about each other:

Steve Jobs. vs. Bill Gates. In his autobiography, Steve Jobs had some harsh words for Bill Gates, Apple’s most prominent competitor. “Bill is basically unimaginative and has never invented anything, which is why I think he’s more comfortable now in philanthropy than technology,” he wrote.
When prodded about the diss on ABC News, Gates responded with diplomacy and respect (reasonable, since Jobs had just died). “I respect Steve. We spurred each other on, even as competitors. None of that bothered me.”

George Raveling vs. Lavar Ball. Retired football and basketball player Lavar Ball has fouled up the sport, according to Nike executive George Raveling. Ball, owner of Big Baller Brand is, according to Raveling, “the worst thing to happen to basketball in the last hundred years.” 
Ball retaliated quickly in an irate Instagram video. “That’s because everybody been in darkness for 100 years,” he retorted. “We in a new lane, baby. That Big Baller Brand about to be your competition.”

We coming #BBB

A post shared by Lavar Ball (@lavar) on

Evan Spiegel vs. Mark Zuckerberg. Snapchat CEO Evan Spiegel, in an interview with Forbes, described Zuckerberg’s request that the two meet for a business negotiation as fairly desperate and noted that the Facebook CEO was “ready to surrender.’” According to an acquaintance of Spiegel’s, his account was a fabricated swing at Zuckerberg. The real email correspondence, the contact wrote, “reads more like a high school freshman trying to play hard-to-get with the quarterback of the football team.”
Zuckerberg made no response, but he didn’t need to: Spiegel was busted by Business Insider and Forbes itself, and was pressured into revealing the real email exchange in a tweet (which he’s since deleted).

Elon Musk vs. Jeff Bezos. Amazon founder Jeff Bezos was ecstatic when his commercial rocket successfully flew to space and returned to earth in one piece, describing his model as “the rarest of beasts” to his Twitter followers. But Elon Musk couldn’t let that stand: “Not quite ‘rarest’. SpaceX Grasshopper rocket did 6 suborbital flights 3 years ago and is still around,” he Tweeted in response. He proceeded to throw serious shade on Bezos’ rocket for the rest of the day. A month later, when SpaceX launched its Falcon 9 Rocket, Bezos subtly returned the snark, tweeting “Congrats @SpaceX…welcome to the club!”

Marc Benioff vs. Larry Ellison. Roughly 24 hours before Salesforce CEO Marc Benioff was set to give a speech at Oracle’s 2011 OpenWorld trade show, Larry Ellison, Oracle’s CEO, cancelled it. Furious, Benioff tweeted in reference to Ellison’s own speech that “a low bar has been set.” And of Oracle, he wrote “Beware of false clouds.” In response, Ellison repeatedly dismissed Salesforce as an “itty bitty application.” But the two have found common ground since then: Oracle and Salesforce announced a strategic partnership in 2013.

George Clooney vs. Elon Musk. George Clooney, Oscar winner and founder of Casamigos tequila, really doesn’t like Teslas. “I’ve been stuck on the side of the road a while in that thing,” he told Esquire. “Why am I always stuck on the side of the f–ing road?” Musk wasn’t having it, tweeting back “In other news, George Clooney reports that his iPhone 1 had a bug back in ‘07.”