A "viking" was historically someone that went out and traded/plundered/pirated/etc in the ice free part of the year. As a business. (There are historical documents of a Danish king recruiting in Uppsala for an English vacation.) No need to move anyplace to be a viking. Such things aren't unknown in clan cultures (see e.g. Afghanistan).

As I wrote in another comment, you find neonazis in Israel, that doesn't mean they are numerous. Today in Scandinavia, the left wing idiots in organized groups seems more violent than ND etc. I might be wrong, you got a reference?

Edit: Otoh, the word "Viking" has been used for so many things it has lost all specific meaning long ago. :-)