230 F.2d 357 (7th Cir. 1956) Cited 25 times
Stating that employer can prohibit employees from wearing buttons emblazoned with the slogan "Don't be a Scab" because of slogan's inherent tension to incite unrest and resentment; however, the restriction does not include "passive inoffensive advertisement of organizational aims and interests . . . which in no way interferes with discipline and production"