The people leading the demonstration were Neturei Karta. I’m sure they protested anything overly Anti-Semitic since they say they are just against Zionists not Jews.
(Satmar Rebbe zt”l said about Neturei Karta “Velamalshinim al tehi sikva”. Amein!)
The heter for wearing signs out of an eiruv is an interesting one.