I've just read this and I'm shocked that such a thing could happen. A group of around 1,000 men gathered and assaulted at least 60 women and girls and also pickpocketed people. Apparently the news wasn't released until now out of fears it could stir up tension as the men appeared to be of Arab/North African appearance, possibly refugees.
abcnews.go.com/International/wireStory/cologne-police-chief-condemns-sex-assaults-years-eve-36083833