8 LINDKE v. FREED Opinion of the Court properties or platforms” is part and parcel of it. Halleck, 587 U. S., at 816. Thus, if Freed acted in his private capacity when he blocked Lindke and deleted his comments, he did not violate Lindke’s First Amendment rights—instead, he exercised his own. So Lindke cannot hang his hat on Freed’s status as a state employee. The distinction between private conduct and state action turns on substance, not labels: Private parties can act with the authority of the State, and state officials have private lives and their own constitutional rights. Categorizing conduct, therefore, can require a close look. III A close look is definitely necessary in the context of a public official using social media. There are approximately 20 million state and local government employees across the Nation, with an extraordinarily wide range of job descriptions—from Governors, mayors, and police chiefs to teachers, healthcare professionals, and transportation workers. Many use social media for personal communication, official communication, or both—and the line between the two is often blurred. Moreover, social media involves a variety of different and rapidly changing platforms, each with distinct features for speaking, viewing, and removing speech. The Court has frequently emphasized that the state-action doctrine demands a fact-intensive inquiry. See, e.g., Reitman v. Mulkey, 387 U. S. 369, 378 (1967); Gilmore v. Montgomery, 417 U. S. 556, 574 (1974). We repeat that caution here. That said, our precedent articulates principles that govern cases analogous to this one. For the reasons we explain below, a public official’s social-media activity constitutes state action under §1983 only if the official (1) possessed actual authority to speak on the State’s behalf, and (2) purported to exercise that authority when he spoke on social media. The appearance and function of the social-media activity are relevant at the second step, but they cannot make