"Cult Alert!" flyers garnished lamp posts on Third and Market Streets the other night -- a siren song if ever we've heard one. (It seems like forever since SF's been plagued with a jazzy, crazy-ass cult. No offense, L. Ron.) In case you missed them, or in case the quality of life sect tore them down, the missives cried out: Cult Alert! Please be advised: Youth With a Mission (YWAM) has been under investigation......