Patent recourse via government redistribution

There is no explicit patent transfer under GPL2, whether the clause in GPL3 would count as an official transfer is debatable. The key point I guess would be that as I read the US code the Government's key to the patent office only applies to the government. In other words, even if the government uses a patented invention you can't sue them for infringement, it's essentially a governmental immunity. Even if the government redistributes they aren't transferring a patent grant so regardless of what the license says you couldn't use it as a work around.