Then Dr. Farley indulged in a bit of theater himself, fishing around in his shirt pocket, saying, “Just to give you an idea, I’ve got one here somewhere,” before pulling out an electronic cigarette that he pronounced “indistinguishable” from a real one. He and other supporters of the ban say e-cigarettes confuse people like bartenders and restaurant owners who have to enforce the existing smoking ban, making that ban harder to enforce. Advocates of e-cigarettes argued they had helped many people stop smoking regular cigarettes, including — based on a show of hands — most of the audience. E-cigarettes, which use a battery to vaporize a nicotine solution, have grown in popularity based on a perception that they are a safer smoking alternative.