> > If A obtains software from the FSF and distributes it to B, who > > distributes it to C who, in turn, distributes it to D, there is a > > license between A and the FSF, B and C, C and B, and D and C. > > If it were so and any of them infringes on the license, then all > downstream users would have their licenses at risk. This situation > would be akin to sub-licensing. But this is not how the GPL works.
As I said, the purpose (and need!) for those licenses is so that you can know that what you are getting IS GPl'ed software: each is certifying to the person they gave it to that there is no other IP involved.
