New laws in New York City and Chicago ban electronic cigarettes from restaurants, bars and other public places.
The bans that go into effect Tuesday are sparking debate among health officials, the e-cigarette industry and users on the future of the popular devices.
Proponents say they're aimed at preventing the re-glamorization of smoking particularly among teenagers who could see them as a gateway to tobacco-based cigarettes.
E-cigarettes have nicotine-based solutions, celebrity endorsers and candy-like flavorings that lawmakers say are appealing to teens.
Users and makers of the vaporizing devices say they were poorly named, causing confusion with combustible cigarettes.
They say the bans ostracize people who want an alternative to tobacco products.
The Chicago ban applies to indoor public places. The New York City law extends to parks and beaches.