So that’s what those unannounced visits by Chinese government officials to Microsoft offices were about.

According to Reuters, the State Administration for Industry & Commerce, a Chinese regulatory body, is investigating Microsoft for monopolistic practices related to Windows. The Chinese government has seized Microsoft documentation, emails, and other information. However, it’s unclear what the charges are, exactly, though it’s possible that Microsoft has violated anti-piracy laws in connection with unverified documents, along with issues related to compatibility and bundling.

The SAIC’s investigation is currently ongoing, allegedly because it was unable to speak to certain Microsoft employees who were not in the country at the time. Meanwhile, Microsoft has enlisted the services of a Chinese law firm to work the case.

“Microsoft really has a dominant market position,”  Zhan Hao, a Beijing-based lawyer at the Anjie Law Firm says. “People rely on it very much and its market share is very high, so this would likely lead to an abuse of its dominant market position.”

Not everyone in the Chinese-based tech business community agrees with this sentiment though.

“It’s ironic they can be accused of a monopoly in a mostly pirated operating system market, as they were criticized for ending support to mostly non-paid versions of Windows XP,” Duncan Clark, an exec with BDA says. BDA is a tech consultant firm.

Microsoft ended support for Windows XP back in April. It’s worth noting that, even though Windows XP is pirated throughout China, Microsoft reportedly partnered with Lenovo and Tencent Holdings to provide Windows XP support to users of the OS based in China.

Former Microsoft CEO Steve Ballmer once said that 95 percent of Microsoft software revenue in China was lost due to piracy.