The Federal Trade Commission told a federal judge on Monday that Meta has abused its power and acted as a monopoly by acquiring rivals instead of competing fairly, opening a months-long trial seen as a test of the Trump administration’s ability to challenge the power of Silicon Valley.

To make its case, the FTC cited Meta CEO Mark Zuckerberg’s own words. Before acquiring Instagram in 2012, Zuckerberg wrote in an internal email that he sought to “neutralize a potential competitor.” And ahead of Meta purchasing WhatsApp, in 2014, Zuckerberg wrote an email saying the messaging service represents “a big risk for us.”