Ad impossibilia nemo tenetur (À l'impossible nul n'est tenu) - on ne peut exiger de quiconque ce qu’il lui est impossible de faire.
Image par Renjith Krishnan
Second prize (my personal favorite) goes to:
"Do not iron while wearing shirt."
to see the rest of the awards: http://abcnews.go.com/TheLaw/wireStory?id=3989557