In 2009, security staff at a Texas bank smelled something funny in the air and asked customers to evacuate because they suspected a carbon monoxide leak. Thirty-four people were rushed to the hospital complaining of chest pains and headaches. Of course carbon monoxide is odorless; the cause of this sudden hysteria turned out to be a strong whiff of a lady’s perfume. But by announcing that there might be something harmful in the air, the context was
created for people to think the worst — and they did.