I have avoided labeling any site listed so that the reader can make up his or her mind. It is important to remember that the label extremist is open to interpretation. One person's extremist group may be another's patriotic group. What a person views as extreme is often a reflection on what he or she believes. That is, extremism is seen though the lens of the mainstream beliefs of the time.
History often tells a different story.
Of course, this may not always be the case. I should say as well, these sites can come and go rather quickly.