I thought that was the exact point the article was making. For example: In addition, Skylink argued that the rolling code was not DRM, since it did not protect

I thought that was the exact point the article was making. For example: In addition, Skylink argued that the rolling code was not DRM, since it did not protect access to some copyrighted computer code but to "an uncopyrightable process" (the opening of a garage door). and: By way of example, DVDs marked 'for home use' or 'non-commercial private use only' are not legally restricted as such. Unless there is a contract, those representations are not true. A given use, e.g., classroom showing, is permitted or infringing depending on copyright law, not what is printed on the packaging—unless there is a contract including that restriction. Rightsholders still print such claims on the packaging, however. They might as well print that infringers are obligated to forfeit their first-born child."