The one that Duss took yesterday? I’m not sure, but Haaretz has an idea:

Opposite the hotel, Bob Kunst, of the rightist group Shalom International, held a one-man protest against the conference with a poster that read: “J St. Nazis.”

That would appear to be these guys. I find it stunning that an organization that professes to be so concerned about the proper commemoration of the Holocaust would call a Jewish peace group Nazis.