This paragraph from the bottom of the article presents a vector of attack (albeit a small one) on the kernel that I hadn't considered before, but it seems like one we may quickly encounter in the future.

"One would guess that a copyright troll with a small ownership [of kernel code] would succeed mostly in getting his or her code removed from the kernel in record time. Big holders could pose a bigger threat. Imagine a company like IBM, for example; IBM owns the copyright on a great deal of kernel code. IBM also has the look of one of those short-lived companies that doesn't hang around for long. As this flash-in-the-pan fades, its copyright portfolio could be picked up by a troll which would then proceed to attack prior infringers. Writing IBM's code out of the kernel would not be an easy task, so some other sort of solution would have to be found. It is not a pretty scenario."