There was even another recent HN submission in the same spirit: http://news.ycombinator.com/item?id=4005906 http://news.ycombinator.com/item?id=4005906 Smoking

There was even another recent HN submission in the same spirit: http://news.ycombinator.com/item?id=4005906 http://news.ycombinator.com/item?id=4005906 Smoking is forbidden on airplanes. But if someone does smoke, it's better that they have an ashtray available rather than starting a fire by trying to dispose of the ashes improperly.