They're not sucking down plain water vapor are they? E-cigs have nicotine cartridges for them, it would be silly to believe that the smokers lungs are grabbing all of that nicotine out before they exhale.
Which is, of course, what this whole thing is about.
Except it's not.
http://www.onlineprnews.com/news/268327-1349236060-new-eciga...
"Those few compounds that were found were at such minuscule levels that toxicology analysis detected no risk (cancer or non-cancer risk) to public health from environmental e-cigarette vapor."
"While secondhand smoke must be eliminated in workplaces and public places, the current data provide no justification for eliminating electronic cigarette use in these places."- Dr. Michael Siegel of Boston University School of Public Health
"For more than 25 years Smokefree Pennsylvania has been advocating indoor smoking bans. Based on the results of this study I see no reason for e-cigarettes to be included in smoking bans." - Bill Godshall of Smokefree Pennsylvania
"The results of this study confirm the findings of my last 4 years of research. E-cigarettes pose no discernible risk to public health." - Dr. Murray Laugesen - Public Health Medicine Specialist, Health New Zealand
https://en.wikipedia.org/wiki/Electronic_cigarette
"In some e-cigarettes, "Tobacco-specific impurities suspected of being harmful to humans – anabasine, myosmine, and β-nicotyrine – were detected in a majority of the samples tested." It is not clear if these chemicals were detectable in exhaled vapour.
The UK National Health Service noted that the toxic chemicals found by the FDA were at levels one-thousandth that of cigarette smoke, and that while there is no certainty that these small traces are harmless, initial test results are reassuring."
So no, it does not appear to be so cut and dry. The whole issue is that it isn't, and some people have a problem with that concerning a product the user shares with everyone around them.
I guess my original comment about not hearing any FUD about e-cigs can be thrown out now.