I don't know how you can make such a bold statement in a seemingly factual manner. Many individuals have suffered various ill health effects from using e-cigs.
Oh yes...add "IMO," and "YMMV" at the bottom which pretty well removes your post from the notion of any kind of fact.
Many people believe that ecigs are the cause of some extremely random health problems, this is true. Generally the rationale is “this thing started to happen to me when I was vaping ecigs”. Sort of a classic correlation/causality fail. This doesn’t mean they didn’t, but whether they actually ARE or not is another question.