Two years before Stanley Kubrick released 2001: A Space Odyssey, he was starting to worry that IBM would get a little mad when HAL 9000, the computer they helped design, came off, well, psychotic.
To ease his troubled mind, Kubrick sent his production company's vice president, Roger Caras, the following letter making sure IBM—whose logo briefly appears in the film—knew what exactly they were getting themselves into.
According to Caras, IBM had no problem with their power-hungry machine or screen credit—so long as they're in no way directly associated with HAL's little murderous rampage or, as they termed it, "equipment failure." While there's long been speculation over the fact that IBM is just one alphabetical shift away from being HAL, both Kubrick and Arthur C. Clarke, the novel's author, have denied any intentional allusion. [Letters of Note via The Atlantic]