I understand that the second (orange) placard was inspired by an actual Darwin Award recipient. Somebody actually Darwined himself rocking a machine trying to get a free Coke.
I'm not sure where it came from; just found it while browsing and saved it to my disk as it made me chuckle.
"Bridge out" is a somewhat North American expression that you won't often hear in Britain, so I would guess this came from the U.S. or Canada. Either way, somebody has a pretty good handle on the way things are going, don't ya think?
This kind of thing spreads though.. I once saw a TV with a stern warning not to use it in a swimming pool.... I assume they meant swimming pool area? or knowing the darwin candidates... maybe not!