Updated

Elizabeth Warren openly sparred with Amazon in a series of pointed tweets on Tuesday, just hours after she admitted during a nationally televised town hall that she still shops at the e-commerce giant -- even though she wants it broken up, along with a slew of other major tech companies.

Warren kicked off the spat on Monday by reiterating her argument that Amazon abuses its control over the Amazon Marketplace, which hosts third-party sellers, to improve its own retail operations and unfairly disadvantage the third-party sellers.

"Giant tech companies have too much power," Warren wrote Monday night, embedding a clip of her remarks at the town hall. "My plan to #BreakUpBigTech prevents corporations like Amazon from knocking out the rest of the competition. You can be an umpire, or you can be a player -- but you can't be both."

In response, the official Amazon News Twitter account wrote Tuesday afternoon that third-party sellers have been doing better than ever.

WARREN VOWS TO SPEND $640B TO PAY OFF STUDENT DEBT -- WHAT ABOUT CREDIT CARD DEBT, VET BILLS, OR MORTGAGES?!

"[S]ellers aren't being 'knocked out' -- they're seeing record sales every year," Amazon wrote, after denying that it uses third-party sellers' data to boost its own products. "Also, Walmart is much larger; Amazon is less than 4% of U.S. retail."

"Oh boy," Warren shot back. "Here are the facts."

The Massachusetts senator then cited "reports" that Amazon used third-party seller data to make its own products successful, and linked to Bloomberg News and Wall Street Journal articles on the topic.

Warren also alleged that Amazon sought to "deliberately misconstrue" its near-50 percent market share in online retail, by instead using brick-and-mortar numbers.

Asked at a CNN town hall on Monday to identify her last Amazon purchase, Warren said she bought a mailbox.

But even though she shops at Jeff Bezos' mega-retailer, Warren told host Anderson Cooper that breaking up Amazon would lead to “a lot more competition where little businesses have a chance to get going.”

In addition to Amazon, Warren previously said she wanted to break up Google, Facebook, and Apple.

Speaking to The Verge at the South by Southwest (SXSW) technology conference last month in Austin, Texas, Warren specifically demanded that Apple must be forced either to surrender control over the App Store or to stop selling its own apps within it.

"Apple, you’ve got to break it apart from their App Store. It’s got to be one or the other," Warren said. "Either they run the platform or they play in the store. They don’t get to do both at the same time."

CLICK TO GET THE FOX NEWS APP

She elaborated: "If you run a platform where others come to sell, then you don’t get to sell your own items on the platform because you have two comparative advantages. One, you’ve sucked up information about every buyer and every seller before you’ve made a decision about what you’re going to to sell. And second, you have the capacity — because you run the platform — to prefer your product over anyone else’s product. It gives an enormous comparative advantage to the platform."

Warren asserted that similar antitrust principles were "applied to railroad companies more than a hundred years ago," and that "we need to now look at those tech platforms the same way."