According to my VOIP service provider website, this phone number belongs to Leland Yee. In other words, this number is either calling to get you to vote or volunteer for Leland Lee for SF Mayor.
I keep receiving calls from this number. If you call back, you just get an answering system that provides no identifying information. If you answer, you get silence and the call is quickly disconnected. Someone wrote that the number apparently belongs to the Leland Lee for SF mayor campaign. I would guess it's more like someone trying to get people angry at that candidate (if it's true that the number is associated with him in the first place). What sane political candidate would campaign using frequent hang-up calls??