The Federal Trade Commission’s high-profile antitrust trial against Meta began Monday in federal court, targeting the company’s past acquisitions of Instagram and WhatsApp. The case, years in the making, could reshape U.S. antitrust law as applied to Big Tech and potentially lead to the forced divestiture of two of Meta’s largest platforms.

Presiding over the case is Judge James Boasberg, who previously dismissed an earlier version of the FTC’s lawsuit in 2021 for insufficient evidence. That case, first filed during President Trump’s first term in 2020, was refiled and expanded under FTC Chair Lina Khan during the Biden administration. In 2022, Boasberg allowed the revised case to move forward, and in 2023 he rejected Meta’s motion to dismiss, clearing the path for trial.

The FTC alleges that Meta illegally monopolized the personal social networking market by acquiring competitive threats rather than innovating. “Acquiring these competitive threats has enabled Facebook to sustain its dominance—to the detriment of competition and users—not by competing on the merits, but by avoiding competition,” the agency wrote in court filings, according to Axios.

The trial—expected to last eight weeks or more—could see testimony from top Meta figures, including CEO Mark Zuckerberg, former COO Sheryl Sandberg, CTO Andrew Bosworth, and past and current leaders of Instagram and WhatsApp. Witnesses from competing platforms, including Snap, TikTok, and Pinterest, are also scheduled to appear.

Meta has defended its acquisitions as vital to the development and success of both Instagram and WhatsApp. “The FTC’s lawsuit against Meta defies reality,” said Meta spokesperson Chris Sgro. “The evidence at trial will show what every 17-year-old in the world knows: Instagram, Facebook and WhatsApp compete with TikTok, YouTube, X, iMessage, and many others.”

Meta argues the FTC’s decision to revisit previously approved mergers undermines regulatory certainty. “More than 10 years after the FTC reviewed and cleared our acquisitions, the Commission’s action sends the message that no deal is ever truly final,” Sgro added. He also criticized the case as potentially damaging to American innovation, especially in competition with Chinese tech firms.

Although Meta and other major tech firms have warmed relations with President Trump during his second term, the FTC’s pursuit of this case signals independence from White House influence—unless the administration chooses to directly intervene.

The case’s outcome will be closely watched as a bellwether for the government’s ability to rein in tech consolidation and redefine antitrust enforcement in digital markets. If successful, the FTC could force Meta to spin off Instagram and WhatsApp, a historic remedy in modern antitrust enforcement. If not, Meta will be further emboldened in its defense of past and future deals.