Extremists and terrorists have found the online sphere, and specifically its social networks, to be an efficient tool for advancing their methods and political needs. The legal responses to the resulting threats from this online activity vary from country to country. The immense importance of the Internet in the everyday life of billions of people worldwide has raised difficult questions regarding the attempt to regulate online activity, especially in relation to the right of privacy and freedom of speech. This report examines how western democracies balance, from a legal point of view, the need to protect their populations from terrorist attacks and their duty to preserve the democratic rights of privacy and free speech.