(http://www.csmonitor.com/var/ezflow_site/storage/images/media/content/2012/0209_naziflag/11715506-1-eng-US/0209_NaziFlag_full_600.jpg)
Here's the original article. (http://www.csmonitor.com/USA/Latest-News-Wires/2012/0209/Marines-Nazi-flag-was-mistaken-for-their-own)
My working hypothesis is that whichever Marine owned the flag was either a Nazi sympathizer or quite possibly a total idiot who didn't know what the flag meant (although if that were true, you'd wonder how he got it in the first place). He then either didn't tell the others what it meant or didn't know. But that the entire unit was full of Nazi sympathizers seems implausible to me -- or maybe I'm just naïve.
FWIW, I didn't recognize it, although it does have a chilling look to it IMO.
EDIT: Poll question and thread title are slightly adjusted in response to comments.