Strange black ring UFO over Anaheim, California

On May 20, 2015, several persons have sighted a mysterious black ring above the city of Anaheim, in California. One of the witnesses has taken some pictures of the phenomenon. Incredible!

Witness statement:

Myself, my wife and many other people witnessed a large, mysterious black ring in the sky above Anaheim CA on 5/20/15. It resembled thick black smoke and seemed to be spinning.

It hovered and drifted in the sky for approximately 2 minutes until it disintegrated.

I happened to see people pointing and noticed it in what I think was the southeastern sky. Its shape and behavior don't match any known aircraft to me either. Definitely very strange!