The Democratic senator from Massachusetts on Thursday took aim at Apple (AAPL), Google (GOOGL), and Amazon (AMZN), saying that they “snuff out competition” and ultimately hurt a smaller company’s ability to compete in the technology industry.

“Google, Apple, and Amazon provide platforms that lots of other companies depend on for survival,” Warren said in a speech in Washington, D.C. “But Google, Apple, and Amazon also, in many cases, compete with those same small companies, so that the platform can become a tool to snuff out competition.”

Warren went on to describe several examples of the companies allegedly engaging in such behavior. She pointed to a 2012 Federal Trade Commission (FTC) investigation into Google abusing its search dominance to hurt smaller companies, as well as the Alphabet subsidiary’s similar troubles in the European Union. On Apple, Warren pointed to the company’s streaming-music service Apple Music, saying that the company has made it “difficult” for competing services, like Spotify, to compete with Apple Music. She also seemed to side with allegations from “thousands of authors” that Amazon tries to “steer consumers to books published by Amazon to the detriment of other publishers.”

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Google declined comment and the other companies did not immediately respond to a request for comment. But Spotify, which is one of the companies competing with Apple Music that Warren might have been referring to, wasn’t shy about her comments. In a statement to Recode, Jonathan Prince, the company’s head of communications and public policy sided with Warren.

“Apple has long used its control of iOS to squash competition in music, driving up the prices of its competitors, inappropriately forbidding us from telling our customers about lower prices, and giving itself unfair advantages across its platform through everything from the lock screen to Siri,” Prince said. “You know there’s something wrong when Apple makes more off a Spotify subscription than it does off an Apple Music subscription and doesn’t share any of that with the music industry. They want to have their cake and eat everyone else’s too.”

Warren’s comments carry significant weight. Earlier this week, the Massachusetts senator was on the campaign trail in support of presumptive Democratic Presidential nominee Hillary Clinton. Many on the left had previously hoped Warren, who has taken aim at a wide range of issues, including inequality, violence, and major companies, would run for President. She’s become one of the more popular Democratic senators in the country. And now, many are hoping Clinton will choose Warren to be her running mate in the fall.

Although tech companies were a concern for Warren, they weren’t the only focus. Her talk at the New America’s Open Markets Program Event centered on the need for more competition in the U.S. marketplace and failure among regulators to protect smaller companies across several industries, including the financial sector, pharmaceuticals, and others.

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That said, while Warren’s tone was decidedly negative towards big companies, she acknowledged that they play an important part in the world. She even said the big tech companies she’s concerned about deserve their success. Ultimately, though, she wants to others get a shot at achieving the same success—something, she argues, they might not have.

“Google, Apple, and Amazon have created disruptive technologies that changed the world, and every day they deliver enormously valuable products,” Warren said. “They deserve to be highly profitable and successful. But the opportunity to compete must remain open for new entrants and competitors that want their chance to change the world again.”