With one major exception, the Roberts Court has been quite protective of unpopular (and even revolting) speech under the First Amendment. That exception, however, is a doozy. It involves a statute criminalizing "material support" for terrorism, and the danger of the law was on stark display this week with reports of a petition to hold Twitter responsible for allowing Hamas to use the service.
First, some background. In 1996, Congress enacted a law that made it a crime to provide "material support" for terrorism. As defined, "material support" included tangible and intangible property, and "services," including financial assistance, training, lodging, harboring, providing false documents, etc., and excepting medicine and religious material. In 2001, the Patriot Act expanded the law to include "expert advice or assistance," which prompted many to argue that the already overly broad law had been expanded to indisputably cover core, constitutionally protected speech.