I'm surprised that KKK is on the list, considering how much that was an American phenomenon. Are there Austrian ultra-nationalists associating themselves with it?
I thought the same thing.
Don't know about Austria, but since the 90s Germany's right-wing extremist scene had a few groups here and there who called themselves "Ku Klux Klan" and did some cross-burnings and stuff. Usually, they're founded by neo-Nazis who are well-connected with the "White nationalist" scene over in the States. Total membership never seemed to exceed double-digit numbers though, so they form one of the more obscure phenomena among Germany's neo-Nazi scene.
They did make the news some time ago however, when two police officers down in Baden-Württemberg were identified as former members of the now defunct "European White Knights of the Ku Klux Klan".