Isn't it already the case that many scanners, printers and image editing software have built-in restrictions to prevent the copying of currency? How are those

Isn't it already the case that many scanners, printers and image editing software have built-in restrictions to prevent the copying of currency? How are those restrictions implemented? I don't mean in a technical sense, I understand the dot pattern recognition. But how is it that the vendors build it in? Are there legal requirements? (and if so, how do Open Source implementations manage) Are they purely concerned about liability? Are they paid to by the proprietors of the technology? (so that the can sell it to mints).