Germany is a country that's deeply, deeply ashamed of its past, of what Nazi Germany did. The slogan used in almost all Holocaust memorials is "Never Again". Most symbolism, gestures and speech that are deemed pro-nazi are illegal in Germany. If you were to, for example, make the nazi salute on the street and shout "death to the Jews!" and "Adolf Hitler", you would get several years of prison, literally.
Except if you are a Muslim.
Groups of Muslims all along Europe, including Germany, are openly and viciously anti-semitic, and will commit acts of harassment and violence against Jews, deface their property and tombstones, and like in the video above, shout anti-semitic and pro-nazi chants. With complete impunity.
It seems that "never again" does not apply to Muslims, not even in Germany. They are untouchable.