I've been trying to follow the online reaction to the Elliot Rodger shooting, and one thing that struck me was the haste with which so many despicable websites (all of which I refuse to link to) have rushed to claim that Elliot Rodger was of at least partly Jewish descent, when nothing in his background would suggest such a thing.
If anything, Rodger's own claims to aristocratic ancestry, his family's supposedly formerly wealthy background, and the very etymology of name "Rodger", all combine to suggest a lineage of old Norman stock; in other words, the very sort of English people least likely to have intermarried with Jews. The only concrete link that exists between the Rodger family and Judaism is that George Rodger - Elliot's father - was among the first photojournalists to document the mass murder at Bergen-Belsen, a fact which ought to stick in the craws of the very types* who are quickest to claim his wayward grandson must have been a Jew.
Considering how easy all of this was to dig up, what can account for the rush to claim a "Jewish" background for Elliot Rodger? I think there are three factors at work here: the stereotypical assumption that anyone working as a director in Hollywood must be Jewish, the desire to minimize the whiteness of Elliot Rodger's background by assigning him to a group that isn't "really" white (at least in the minds of certain sorts), and the conviction that the blame for anything bad that happens in the world can be laid at the rest of a single, supposedly malevolent and all-powerful group. With all three factors, there is a common root cause, namely anti-semitism.
It's no accident that I previously indicated that Elliot Rodger's ideological views owed a great deal to the fetid nexus of "PUA", "MRA", "Red Pill" and oxymoronic "Dark Enlightenment" rubbish, nor is it accidental that just as the PUA, Red Pill and MRA types are now vainly attempting to distance themselves from Rodger, the racists and anti-semites who scurry under the "Dark Enlightenment" label have wasted no time in blaming "race-mixing" or an imaginary Jewish background for Elliot Rodger's deeds. The overlap between the woman-hating, Jew-hating and white supremacist constituencies is substantial, for the blatantly obvious reason that all three types share a belief that being white, male and "aryan" ought to be enough to make one the envy of the rest of humanity.
*By which I mean the sorts who spend most of the rest of their time either denying the Holocaust ever happened at all, or attempting to minimize its scope.