Wolfenstein 3D is banned. It is just not "indiziert" anymore. It is never going to be unbanned because of the unconstitutional stuff (swastikas, HorstWessel Song etc).
I also got the "Sorry, your IP address shows you are coming from a country that requires us to block access to this particular site."
My question is, then, why am I able to play Enemy Territory and go through forums of it?
Bethesda is "proactively overly protective". All their sites have age-confirmation pages before any content. ALL their youtube videos are flagged as potentially inappropiate. I guess for some reason they think they are obliged to follow every country's laws even if they are an USAmerican company (I guess). It really annoys me and makes me think less of them.
As a german it is not forbidden to access such material from all I know. It is also not forbidden to own it or play it. You are "just" not allowed to promote/buy/talk/provide it to others.
Your link is about a different game by the way.