Its much like saying that all palestinians are terrorists. to "go viking" was an action,neither a profession nor an ethnic entity. At the time it was either "landnaam" (landgrabbing) or pillaging-depending on the strenght and size of the party.Given that Iceland was completely unoccupied at the time of Norse settlement (no aboriginal population whatsoever), it would seem wrong to suggest that any landgrabbing was involved. My understanding is, however, that many of the settlers stopped off in Ireland en route to capture slaves, giving Iceland's population its mixed Nordic/Celtic character.
Iceland was settled by people from the West coast of Norway,opposing our first king's unification og the country. Normandy was settled for much the same reason--this time by "viking" -i.e. by force.
This article available online at:
http://www.theatlantic.com/politics/archive/2008/04/an-iceland-update/44099/
