Cigarette companies advertised "light" cigarettes as less harmful to the smoker, although they can deliver the same levels of tar and nicotine.
National Cancer Institute. "Risks Associated with Smoking Cigarettes with Low Machine-Measured Yields of Tar and Nicotine." Bethesda, MD: "Smoking and Tobacco Control." U.S. Department of Health and Human Services, Public Health Service, National Institutes of Health, National Cancer Institute. Bethesda, MD. Risks Associated with Smoking Cigarettes with Low Machine-Measured Yields of Tar and Nicotine. 19 Nov. 2001. 21, 245-246.
On their websites, tobacco companies encourage people to quit smoking. However, in 2006, a court found that tobacco companies manipulate nicotine levels to keep smokers addicted.
"United States of America, Plaintiff, and Tobacco-Free Kids Action Fund, American Cancer Society, American Heart Association, American Lung Association, Americans for Nonsmokers' Rights, and National African American Tobacco Prevention Network, Ontervenors, v. Philip Morris USA, Inc. (f/k/a Philip Morris, Inc.), et al., Defendants." United States District Court for the District of Columbia. 17 Aug. 2006: 5.