826LA is a non-profit organization in southern California that teaches kids how to engage in creative writing. It's known for innovative workshops and clever marketing. We previously featured their time travel store on Neatorama. 826LA has applied that same theme to traditional propaganda posters, producing ten, including the above poster warning time travelers about the dangers of the Butterfly Effect.
Link via io9
and not Edward Lorenz when it comes to the butterfly effect, especially when it comes to time travel.