Pioneer-12 disputes the application of the GFDL to his signed
contributions on talk namespace, a fact that only became apparent to me a
few minutes ago, but he has continued to contribute disputed material to
talk space.
To avoid further disputed material being contributed I have blocked him--I
know this is going to be controversial because he hasn't really done
anything "wrong", it's just a legal dispute between him and Wikipedia, so
I'm not going to engage in arguments over this, but it seems to me like
the best way to limit the potential damage.