there are plenty of Republican Leakers inside the White House, maybe Schiff and company are concerned that House Republicans might leak the identity of the WB, and have him assassinated?
sounds farfetched, but in the crazy environment we are in, that thought can't be off the table. when Trump has already called the WB "treasonous", and a "Spy", it only takes one right-wing crazy with an AR-15 to "get even".