The Ernst Bettler hoax
In the 1950s a designer called Ernst Bettler was asked to design posters for a Swiss pharmaceuticals company. The company had been involved in testing drugs on prisoners in German concentration camps during the Second World War, and Bettler decided to subvert it from the inside. His posters were innocuous enough on their own, showing black and white relatively abstract portraits behind clean sans serif text. But if placed together, the abstract portraits spelled out letters – N, A, Z, and I. The posters caused riots and six weeks later the company went out of business.
A nice story, you might think – and numerous magazines and books thought so too. Nice, except for the fact that it’s entirely made up. You can find out more here at the Design Observer about how the story first featured in Dot Dot Dot magazine and went on to be repeated.
A great example of an entirely fictitious story becoming received wisdom: because it said what people wanted to hear, and because nobody bothered to check its sources.