yes, it has a star of david on it. Which makes sense, they oppose the vatican, so they would naturally support judaism (sp?). Also, the star of david is not JUST a jewish symbol, as it is used in some non-religious instances. Sort of like how the manji symbol being the root of what a swastica is, but means something entirely different.
I'll tell you something that my friend had to deal with. She was cosplaying a character from hellsing that wore a swastika. It wasn't a symbol similar to a swastika, it was an actual swastika. She normally wears it with the costume with no worries, as she doesn't really feel that certain characters should be offlimits to cosplay because of stuff like that. However, shortly after hurricane katrina, there was a convention she went to in dallas, and dallas then had a LOT of people, particularly minorities of all kinds, that weren't from the area or familiar with anime staying in the hotel that the convention was at. She chose not to wear the swastika because those people weren't expected to know anime, and wouldn't understand that she wasn't actually supporting the notion of being a nazi.
So use your own judgement. If you're in an area where virtually everyone is a con-goer, then they are expected to assume you're just cosplaying a character, and ask you, or someone else, what the character is about. If your in an area where there are still tons of civilians, and many people who won't even guess that you are dressed from an anime you might go with leaving the armband off.