FSF Files Suit Against Cisco For GPL Violations
But, since these files are key to IOS as well, one could take the view that IOS is now under the GPL.
To prevent scare-mongering: This isn't how GPL viralness (virality?) works. Assuming that they have mixed IOS with GPL code in a way that would "infect" IOS (they'll argue that it doesn't, of course) they can either 1) GPL IOS to bring everything into compliance (fat chance) or they can stop doing that, stop distributing the stuff they have, pay a big fine, and rewrite everything in a hurry and at great expense - exactly what Linksys did before them. IOS being forcibly placed under the GPL is a vanishingly unlikely possibility (not even sure that a ruling that they must do so would be legal).