Something is fishy about this story

"A gang of anti-Semitic thugs roughed up a Jewish man and his wife on the Upper East Side on Monday evening before fleeing in cars flying Palestinian flags, police sources told The Post.  Two cars and multiple motorcycles pulled up to the couple on East 63rd Street near Third Avenue just after 8 p.m., and the assailants began yelling “anti-Jewish statements,” the sources said."  Let us forget about the details of the story, how would the thugs know that the man and his wife are Jewish?  And those who decided to openly fly the Palestinian flags decided that the most hospitable place for them is the Upper East Side?