Here's a new angle on this situation: On the tube yesterday, I saw a sign showing an abandoned piece of luggage on a seat and reading: "Don't touch, check with other passengers, inform station staff or call 999."
In other words, if you just ignore the bomb, maybe it will go away. For the want of a semi-colon, the train was lost.
Of course, the US is as full of badly worded signs as is England. At my old office, there was a sign on a door reading, "This door must be kept closed at all times." Wouldn't a wall have been a better choice than a door, in that case?