( To krismiller): Visiting Krabi / Ao Nang a few years ago, there were notices on the beach that unauthorised release of these lanterns would result in a 3000 Baht ( about £ 75 or 80 euro ) fine; can't comment on other Thai resorts nor how vigourously the law is enforced, but seems a reasonable law to me. First saw one of these on Christmas night some years back (in native Scotland) and it soared to a considerable height before I lost sight of it - yes, a potential threat to aircraft.