Four small tech firms filed a class-action lawsuit in the US District Court for the Northern District of California on Thursday, accusing Facebook and its CEO Mark Zuckerberg of running a vast anticompetitive scheme in an attempt to solidify long-term market dominance.

The plaintiffs include Cir.cl, an online marketplace and social network; Beehive Biometric, an identity-verification firm; Reveal Chat, an online chat application; and Lenddo, a financial services firm. The first two companies are now defunct, having dissolved prior to filing the suit.

The suit alleges that when Facebook’s social network dominance was threatened by the rise of social networking apps designed for smartphones, it engaged in a series of anticompetitive activities to either destroy or acquire competitors. The complaint focuses especially on Facebook’s ownership of WhatsApp and Instagram, and Facebook’s plan to integrate the apps into Facebook’s own Messenger app. The plaintiffs claim that if Facebook is allowed to move forward with the integration, it “will imbue Facebook with unrivaled global dominance of the Social Data and Social Advertising Markets.”

The companies are asking the court to force Facebook to divest itself of both WhatsApp and Instagram. Additionally, the companies claim that, because of his uncontested control over the company, the court should order Zuckerberg to sell his majority stake to prevent his continued abuse of Facebook’s power and dominance in the social networking sphere.