[greenduck]

Expanding on what katbyte said, the Hays code was adopted by every major studio in the US to replace state run censors. They did this because of the same battle going on right now in social media: "if we self regulate, then we won't need government regulation placed on us." When an entire industry agrees to follow the code and has enforcement options available and does it with the threat of government action if they don't follow it, the only difference between it and a real law are the name. The consequences to ignoring it were that your funding was dropped, the offending scenes were removed from the film, or you were kicked out and blacklisted from the industry. They were apparently pretty strict about it. You can tell that by how stringently it was followed for decades.

[iguy]

And the big players had a stronger monopoly than seems possible today. Downloading obscure foreign movies isn't quite as easy as Netflix, but in 1960 what wasn't on TV or a few screens was just about unobtainable for almost everyone.

(I guess paying for these downloads runs into a similar situation, mastercard & friends choose to ban things they aren't legally required to.)

[garrettgrimsley]

They were likely taking issue with the statement “de facto against the law.” De jure is by law and de facto is in fact, and using them how that poster did does not make sense.