Any time we walk outside with a cold, use your car, drive on less than 8 hours of sleep, or choose not to get a flu vaccine we put other people&#x27;s health at risk.  We accept a certain level of risk to function as a society.  If the acceptable threshold of risk was less than &quot;possible threat to another person of any magnitude&quot; we would be a very different society.  It seems to me that we use a different rule to decide when to ban activities which is &quot;good evidence of substantial amount of harm(drinking and driving, or second hand smoke)&quot;.  I would argue that in order to ban e-cigarettes we need to wait for evidence that e-cigarettes are likely to cause significant harm to bystanders.