CEP reports weekly on methods used by extremists to exploit the Internet and social media platforms. Featured in this edition, CEP researchers located a site on the dark web for the pro-ISIS Electronic Horizon Foundation, also known as Horizon. Horizon was founded in January 2016 in order to improve the web security of ISIS and their online supporters. The website, accessible with Tor, a web browser that anonymizes one’s web traffic, is available in Arabic, English and French. Platforms covered include Telegram, Riot, Signal and OONI probe. Operating systems include iOS, Android, Windows and Linux.