Over the past several years, Microsoft has largely managed to withstand populist calls to break up Big Tech while peers faced sweeping lawsuits. But a probe by the Federal Trade Commission suggests that grace period could be nearing an end.

Earlier this year, Bloomberg outlined the contents of civil investigative demands (CIDs) — similar to a subpoena — the FTC sent to at least half a dozen companies that compete with Microsoft. New details obtained by The Verge further reveal the FTC’s interests, suggesting the agency is particularly concerned with potentially exclusionary behavior around Microsoft’s Azure cloud services, as well as its role in the AI industry.

There’s no guarantee the investigation — which began under the Biden administration in 2024 and continued under President Donald Trump — will end in a legal complaint. After further investigative steps, FTC staff will choose whether to recommend filing one, and the agency’s two commissioners will take a vote. Should they approve a lawsuit, however, Microsoft may find itself back in a hot seat it occupied more than two decades ago, when a court found it had an illegal PC operating system monopoly.

The Verge obtained previously unreported information about the letters from an industry source who reviewed them and was granted anonymity to speak on nonpublic information. The Verge further verified the document. The questions show the FTC gathering information on industry practices and competitive stumbling blocks, asking about Microsoft’s business agreements, licensing arrangements, and interoperability of its products. The documents generally span more than 15 pages and over 15 questions, often with extensive sub-parts.

The CIDs say the goal of the FTC probe is to determine if Microsoft has used unfair methods of competition in its cloud, software products, and related services in violation of the FTC Act, the source says. The FTC did not respond to a request for comment. Microsoft spokesperson Alex Haurek says that the company is “cooperating fully with the FTC and believe our practices promote competition while delivering the innovative products our customers expect.”

Customers have complained — often anonymously for fear of retaliation — that Microsoft’s 2019 changes to its licensing terms made it significantly more costly to run Windows software on infrastructure outside of Microsoft’s Azure cloud. In 2023, Google responded to a broad FTC inquiry about business practices in the cloud computing industry by accusing Microsoft of using dominance in other areas to “give their own cloud products an unearned advantage” and lock in consumers. Microsoft insists there’s plenty of competition in the cloud sector, and Haurek pointed to Google as “a clear example of that dynamic—growing 63% year over year and competing head-to-head with other major providers including AWS, the largest cloud provider.”

Shortly before the investigation was reported, a 2024 ProPublica investigation found that Microsoft used similar leveraging to gain a foothold across US government agencies after installing free cybersecurity upgrades that came with products that specifically ran on Azure, which would be strenuous to switch away from later on. (Government contracts and cybersecurity were not among the CID topics disclosed to The Verge, and Haurek says Microsoft responded to the government’s security requests at the time and that agencies were “free to engage with other vendors.”)

This kind of information gathering tends to occur at the earlier stages of an investigation, according to George Washington University law professor and former FTC Chair William Kovacic. The two-member, all-Republican commission could choose to end it quietly without bringing a complaint, with no minority party commissioners to object or publicize the choice.

Some of the CID questions seem aimed at understanding the cloud industry, including questions about company organizational charts, business and marketing plans, and product roadmaps. It asks the companies to detail plans for bundling multiple features and products, as well as pricing, discounting, and profitability. Other questions appear to probe how challenging it is to break into a market that Microsoft operates in, asking about the costs and barriers to entry involved in entering or expanding into these markets. The FTC asks specifically about Microsoft’s impact on competition, soliciting documents that speak to the impact of Microsoft’s policies or market position as well as details about overall industry bundling and interoperability practices, including at Microsoft.

The agency asks some similar questions about competition around AI products, including competing for customers against businesses that combine extra features or services with an AI or software product like Microsoft 365.

The questions suggest the agency is trying to determine which key market players to watch and how important tactics like bundling are, Kovacic says. The references to AI could suggest that the FTC considers it a potential part of an illegal tying arrangement or an important competitive advantage.

The US isn’t the only country that’s been probing this issue. The European Commission, UK Competition and Markets Authority, and Japan Fair Trade Commission have been investigating Microsoft’s cloud services within the last year. Haurek says Microsoft is “committed to working quickly and constructively with the CMA” on its review and is also cooperating with the investigations in Europe and in Japan, where the cloud sector “has never been more dynamic and competitive.”

As a $3 trillion company, it’s “almost inevitable” for Microsoft to become a target of third-party antitrust complaints, Kovacic says. In the US, Microsoft has already faced a government challenge of its Activision Blizzard acquisition, but ultimately prevailed, and has yet to face a true recent breakup threat like Google, Meta, Amazon, and Apple.

So far, Microsoft has been largely absent from the calls to break up Big Tech reverberating through political campaigns and the halls of Congress. The company’s business-focused offerings have helped it dodge child safety and moderation fights that can create political enemies. Kovacic also credits Microsoft’s adaptation after its earlier monopolization case, saying it’s generally regarded in the industry as “having the best compliance program” and “the best approach to dealing with the regulators.”

In a landmark 1998 complaint, the Department of Justice accused Microsoft of illegally tying its dominant Windows operating system to its Internet Explorer browser, boxing out competitors. While a court ruled against Microsoft, the government ultimately settled, allowing it to avoid a breakup. Still, the case is often credited as reining in Microsoft and allowing then-nascent firms like Google to flourish.

A case against Microsoft could impact the AI industry as a handful of companies are vying for market share. Even when tech companies prevail, antitrust suits can require years of litigation and put internal business operations under a microscope. Though none so far have resulted in a breakup, Apple and Google are both under court orders that restrict anticompetitive business practices. Apple and Amazon’s trials have yet to take place.

Kovacic says it’s really the totality of tech antitrust cases that could tip the scales. “The direction of the entire information services sector is going to depend on the resolution of this very large number of pending cases and investigations involving Big Tech,” he says.