This video is identified in the YouTube description as being taken by an Occupy Oakland protester.
“Flying Saucer Over Oakland; Alien UFO, Korean BBQ. I was visiting an art exhibit that night in the Art Murmur district of Oakland, having just had Korean BBQ. The ship or whatever it was was the size of a small car, and zip past overhead. I ran down the gallery atrium and out the front door. The ship had frozen just over the restaurant across the street. It wavered and pulsed over the restaurant, as if absorbing something. I was startled.”
Check the full video.