As I sat waiting for my flight, a voice over the PA system regularly reminded me that smoking is not permitted in the airport. Considering that smoking in airports was banned in 1976, 47 years ago, it seems like an awfully long time to keep reminding people of something that has become the expected behavior. Perhaps they could advise people of other forbidden activities, ones that are maybe not so obvious.
Attention passengers: Racing raccoons for the purposes of gambling is forbidden in all areas of the airport, except in the employee parking lot. Personal comfort grizzly bears over 500 pounds in weight must be on a leash at all times. Shirtless bareback donkey riding while carrying a long-bow will result in a fine of $385. Please remove all fruits and vegetables from your trousers before proceeding to security screening. Pickaxes, broadswords, and war hammers are not permitted as carry on items and should be checked through to your final destination. Passengers in the international terminal are advised that if they see someone committing regicide, they should report it to security or call 911.
Can you believe that they used to let people smoke on the airplanes? There was a smoking section in the middle of the plane, and of course the smoke stayed right in that spot, no drift or diffusion. The airlines had an agreement with the universe that the smoke would stay where it was put. A long time ago, but they still have to light up the no smoking signs just to remind people of an obvious rule.
The amount of information communicated by a message depends on its content. The lower the probability of a message occurring, the greater the information it contains. The information sent from a source when the j-th message is transmitted is given by:
Where 
We are experiencing turbulence and have turned on the no alligator sign. Please stow your alligators under the seat in front of you or in the overhead bins, would be a really informative message because no one is expecting it.
I’ve said too much. Enjoy your death trap, ladies.
—DG
Inside Doug's Head 