Why do I see No Smoking signs in the windows of restaurants?

In the 1990s, when the dangers of second-hand smoke became widely known, may laws were passed in the United States to protect nonsmokers from having to inhale another person’s smoke. Some of these laws prevent people from smoking in public or government buildings. Nonsmoking sections in restaurants have grown larger and larger, with many restaurants banning smoking altogether. Smoking is banned in most office buildings. California and New York have also passed statewide laws banning smoking in public places.