Recent acts of terrorism and hate crimes have prompted a renewed focus on the possible links between internet content and offline violence. While some have focused on the role that social media companies play in moderating user-generated content, others have called for Congress to pass laws regulating online content promoting terrorism or violence. Proposals related to government action of this nature raise significant free speech questions, including (1) the reach of the First Amendment's protections when it comes to foreign nationals posting online content from abroad; (2) the scope of so-called "unprotected" categories of speech developed long before the advent of the internet; and (3) the judicial standards that limit how the government can craft or enforce laws to preserve national security and prevent violence. At the outset, it is not clear that a foreign national could invoke the protections of the First Amendment. The Supreme Court has never directly opined on this question. However, its decisions regarding the extraterritorial application of other constitutional protections to foreign nationals and lower court decisions involving speech made by foreign nationals while outside of the United States suggest that the First Amendment may not apply in that scenario. In contrast, free speech considerations are likely to be highly relevant in evaluating the legality of (1) proposals for the U.S. government to regulate what internet users in the United States can post, or (2) the enforcement of existing U.S. laws where the government seeks to hold U.S. persons liable for their online speech. Although the government typically can regulate conduct without running afoul of the First Amendment, regulations that restrict or burden expression often do implicate free speech protections. In such circumstances, courts generally distinguish between laws that regulate speech on the basis of its content and those that do not, subjecting the former to more stringent review. A law that expressly restricts online communications or media promoting violence or terrorism is likely to be deemed a content-based restriction on speech; whereas a law that primarily regulates conduct could be subject to a less stringent standard of review, unless its application to speech turns on the message expressed. Whether such laws would survive First Amendment scrutiny depends on a number of factors. Over the past 50 years, the Supreme Court has generally extended the First Amendment's free speech protections to speech that advocates violence in the abstract while allowing the government to restrict or punish speech that threatens or facilitates violence in a more specific or immediate way. The subtle distinctions that have developed over time are reflected in the categories of speech that the court has deemed unprotected, meaning that the government generally can prohibit speech in these areas because of its content. These include incitement to imminent lawless action, true threats, and speech integral to criminal conduct. Although judicial decisions have helped to define the scope of some of these categories, open questions remain as to how they apply in the context of online speech. For instance, legal scholars have questioned what it means for speech to incite "imminent" violence when posted to social media. They have also asked how threats should be perceived when made in the context of online forums where hyperbolic speech about violence is common. The extent to which the government can regulate speech promoting violence or terrorism also depends on whether its law or action satisfies the applicable level of scrutiny that the Court has developed to evaluate measures that restrict or burden speech. In general, laws that regulate protected speech on political or ideological matters are subject to strict scrutiny, but in some cases, courts have concluded that the government's national security interests justify restrictions.