You may be right about the open anti-Semitism coming from non-Muslim Dutch, but we have seen one too many stories from Europe (especially France) that goes out of its way not to mention that perpetrators are, in fact, Muslims. And considering Rotterdam is such a Muslim city, it would not surprise me if this were caused by Muslims.
I don't know if it's appropriate to post these links on FR, but Dutch skinhead sites keep active lists of Joooo politicians, members of media, university educators, business owners and their businesses etc. Along with family members names and bio info. Updated regularly, and is quiet extensive. Along with contact info, addresses, and some photos of the most prominent politicians. Displayed against Holocaust pictures, and calls for the death of all Joos. Open forums for the world to see.