A digital signature is reasonable if it can be used to produce a warning but not a denial. In other words, if my computer wants to pop up a “This will void you

A digital signature is reasonable if it can be used to produce a warning but not a denial. In other words, if my computer wants to pop up a “This will void your warranty!” warning the first time I plug in a cheap peripheral that has not been validated, I think that is fair use and buyers are free to continue and accept any consequences. On the other hand, I do not think the original manufacturer has the right to outright prevent the use of unsigned-but-standards-compliant devices, since that wanders into “you actually leased and never owned your device” territory.