"Benzos," benzodiazepines, are prescribed by the gallon but do they work? And even if they do, are they safe to use? Herd immunity - what is it, do we need it? Obesity - genetic or not? if it is, what is does it mean? Smoking: New research says smoking kills in many ways besides lung cancer and heart attacks. I don't spend long on this because who doesn't know smoking kills? And in case there's any doubt, second-hand smoke kills millions too.