A ban on smoking in public places has come into force in China. The move is aimed at curbing the number of deaths from smoking-related diseases and protecting the health of other nonsmoking people. But the ban has been questioned on its effectiveness because it doesn't specify any penalty for those violating the rules. The number of smokers in China stands at around 300 million. Many businesses don't welcome the ban because of the complaints about such rules from their customers who smoke. The ban prohibits smoking in public places such as hotels, restaurants，theatres, and waiting rooms at railway stations, but not in the workplace.