Weekend at Larry's: What happened at the Ellison estate?

What's he building in there? A tipster sent this Larry Ellison spy report on Saturday:

Something big at Larry Ellison's today. About a dozen san mateo sheriffs watching the road and at least 20 private security in front of the gatehouse of his Woodside Japanese estate on Mountain Home Road.

If Larry Ellison's housekeeping staff is reading this, help the press out: ¿Qué pasó en la casa de Ellison el sábado?