Seeking to slow the flow of revenue to the studios, CSU also picketed theaters, which the studios had acknowledged more than once as their ne plus ultra. These pickets at theaters became a favored CSU tactic—they were described as the “‘atom bomb’ of the present struggle”; this strategy allowed CSU to harm the box office, while involving whole communities across the nation in its crusade.44 One group picketing the thriller Lady on a Train told potential customers: “Save your money. We’ll tell you all about it. Don’t be fooled by Dan Duryea—Ralph Bellamy did it. He’s the killer. And David Bruce gets the girl!”45 Soon two L.A. theaters agreed to drop any movies made at “unfair” studios until the strike was settled. When “pioneer movie producer D. W. Griffith refused to pass the Paramount theater picket line,” CSU knew that it had devised a sound tactic that could potentially drain the all-important box office receipts.46 CSU began to develop its own blacklist of stars who crossed its picket lines, a growing roster that came to include Rosalind Russell, Robert Montgomery, John Wayne, Leo Carrillo, Humphrey Bogart, Susan Hayward—and many more.47