They've become a common sight on city streets everywhere: e-cigarettes. The industry has boomed in recent years, with a huge uptake in users around the world. But one of the groups taking up vaping faster than any other are teenagers. In the United States, lawmakers are trying to crack down on sales to teens, citing health concerns over nicotine addiction. So is vaping a better option than traditional cigarettes? Or have the health risks been downplayed? And are these companies targeting teens? CNN Chief Medical Correspondent Dr. Sanjay Gupta joins Max Foster, along with Jacqui Smith, Stig Abell and Iain Dale.