Now the funnier thing about this picture is the explanation as to what the dubious looking sign is supposed to mean. Jag says:
"I am told that from left to right - it means:
1. person with injured arm 2. person holding a child 3. pregnant woman 4. person with injured leg
But when I looked at it - it seemed to convey something rather different! If it's not a hoax - then Japan can be an awfully confusing place!"
Update - D'OH I thought this was too good to be true - it definitely looks like a spoof sticker now, but the "original" the "hoax" is based on still looks very funny, see Fernando Serboncini's comments below.