This paper investigates what role fundamental rights can play in the interpretation of EU antitrust law, in particular Art. 102 TFEU. It spells out the difficulties that derive from the fact that antitrust law and fundamental rights are of equal ranking in the EU legal order. It concludes that nevertheless as a matter of systemic and teleological interpretation, EU antitrust law is open for fundamental rights considerations. However, recourse to fundamental rights should be taken only when companies possess regulatory power. This approach sheds light on social media platforms’ recent increased engagement in content moderation. It suggests that for dominant platforms with regulatory power, any discrimination based on political beliefs is prima facie abusive behaviour under Art. 102 TFEU. However, such conduct may be justified by the pursuit of legitimate goals and companies should be granted a wide margin of appreciation in that regard.