E-cigarettes have had some quality-control issues. Plus, most e-cigs contain addictive nicotine, and carcinogens have been found in some e-cig vapor. How about we get some more research and regulation up in here?
Cobb, Nathan K., et al. "Novel Nicotine Delivery Systems and Public Health: The Rise of the “E-Cigarette"." American Journal of Public Health. 100(12). Dec. 2010: 2340–2342. Web.
Schober, Wolfgang, et al. "Use of electronic cigarettes (e-cigarettes) impairs indoor air quality and increases FeNO levels of e-cigarette consumers." International Journal of Hygiene and Environmental Health. 217(6). July 2014: 628–637. Web.
http://www.sciencedirect.com/science/article/pii/S1438463913001533
Cobb Nathan K., and David B. Abrams. "E-cigarette or drug-delivery device? Regulating novel nicotine products." The New England journal of medicine. 365(3). 21 July 2011: 193-195.