https://tonari.wordpress.com/2015/09/05/eine-kerze-gegen-rassismus/

Frau Tonari reminds that all over the world a candle may be placed in the window. The candle symbolizes that you are against racism and against hate of foreigners.

It seems to me, the lighting of a candle may contribute to uniting people in peace and friendship. What a peaceful world it would be if nobody would get attacked any more!