I heard a story (that I'm having trouble finding now) that in the early days of the Rebbe’s leadership, there was a bakery in Crown Heights about which unfounded rumors were spread and people stopped shopping there. The owners were extremely distressed, they were going to lose their livelihood. Then one day, the Rebbe got someone to buy a cake from them, and the Rebbe made sure to be seen walking in 770 holding the cake. Needles to say, people weren't concerned about the rumors any more.