I can just imagine the entire population of London being in underground shelters with 1000000 cans of spaghetti and meatballs
but without a can opener :D
Of course it's not :) It's just a parody some guy made based on signs that have been (presumably) made by an official source.
As swag said, a similar thing happened with flight safety manual diagrams, that was pretty damn funny :)
Me too :D