Penn Jillette was talking about this on his radio show last week.
As Wade relates the incident:
The writers jumped on the idea and Superman … began trouncing the Klan over the airways, a battle replete with obviously authentic detail. During the first broadcast, “Doc” Green received a phone call from the Atlanta AP bureau chief:
“Superman’s really on your trail … sounds to me like Superman’s got a pipeline into your klaverns somehow. You’d better watch your step.”
“I smell a rat,” the Dragon said bitterly. “Just wait till I get my hands on him!”
“You’d better make it snappy–Superman just flew over your Imperial Palace to case the joint.”
“Nuts,” the Doctor said, and hung up.
Green had to change his passwords because of the show. The Klan chief tried to retaliate by pressuring Pep Cereal–sponsors of the Adventures of Superman–off of grocery shelves in Atlanta. Despite Green’s actions, the sponsors continued to green-light the anti-Klan shows.