If you will be flying on an American Airlines 767-300, you might have quite a few empty seats around you. It seems American installed additional business-class seats on 58 767-300’s and now there aren’t enough life vests for all the passengers.
American states that no one was ever in danger since they also have life rafts aboard (personally, not as assuring if you are on a plane going down into water and all those around you have life vests on and you don’t).
Source: Chicago Tribune Image: Van-Murph