Product placement is a time-honored tradition in commercial cinema. But it seems merely getting their products in the hand of movie characters is not enough for some companies. Writer-director Rian Johnson recently revealed a strict policy put in place by Apple regarding films using their products.

"Apple, they let you use iPhones in movies but, and this is very pivotal if you're ever watching a mystery movie, bad guys cannot have iPhones on camera. Every single filmmaker who has a bad guy in their movie that's supposed to be a secret wants to murder me right now."

So if you see any character in a movie pointedly sporting the latest iPhone for the camera, you can rest assured that the person will turn out be a class act who is in no way responsible for anything bad that happens in the movie.

It seems Apple has an extreme aversion to anything that can be construed as bad publicity for their products. And we can see why that is. After all, Apple stays ahead of the competition in large part thanks to the image it has built up among its devoted fanbase as a cutting edge company that caters to the visionaries and creatives of society. Apple clearly does not want to give the impression that its user base also includes bad guys who would plan their evil schemes using the iPhone calendar app or kick off a crime spree to music set by their iTunes playlist.

Johnson's explanation about Apple's policy was part of a masterclass session he did for Vanity Fair where he explained how he set the stage for his runaway hit mystery-thriller Knives Out.

Keeping the audience guessing who the real culprit in the movie was was a big part of the appeal of the film, which is why having to follow a policy like Apple's can be a hindrance to that kind of filmmaking.

On the other hand, under the right circumstances, product companies are happy to shell out huge amounts of money to have their products featured in films, which takes some of the monetary pressure off of the production companies and allows them to recover some of their investment before the film ever gets released.

With the breakout success of Knives Out, fans are eagerly waiting for a sequel. Johnson has spoken in the past about his desire to make a worthy sequel instead of a half-hearted cash grab. To that end, he has firmly maintained that he will only move forward with the sequel once he has written a script that is worth making into a movie.

The Knives Out sequel is set to be a completely new criminal case, investigated by Benoit Blanc, the gentleman detective viewers were first introduced to in the original film. Daniel Craig will be reprising his role as Blanc, and the actor has already expressed his enthusiasm for a sequel that allows him to step back into the role of the mystery solver at the center of yet another case that has baffled the police.