Article 10(1) of the European Convention on Human Rights, freedom of expression, is incorporated into UK law. With the growing Islamist terror threat after 9/11, particularly threatening European security, the Council of Europe introduced the Convention on the Prevention of Terrorism (CPT) 2005. One of the Articles within the Convention, Article 5, obliges states to outlaw ‘public provocation to commit a terrorist offence’. Drawing on its obligations in the CPT, the UK enacted section 1 of the Terrorism Act 2006: ‘encouragement of terrorism’. But, in implementing its duties, the UK went further. There are very real concerns, therefore, about the effects of this legislation on freedom of expression. The test for interpreting breaches of Article 10 is ‘proportionality’. Comparatively, in America there is a much stronger test than proportionality, ‘strict scrutiny’, in assessing limits to terror speech. However, in the age of Islamism, together with the speed, ease and little cost incurred in sharing terror speech online, should there not be a reappraisal of American law? The author is based in the UK. But the UK’s approach to limiting terror speech is arguably too intrusive of freedom of expression. This paper, therefore, proposes a compromise approach between the two jurisdictions.