This case is proving a tough nut to crack: Thieves have been making off with shipments of walnuts and almonds in California's Central Valley. The latest heist is valued at $400,000. Rich Paloma, a reporter with The Oakdale Leader, tells NPR's All Things Considered that in the most recent nut job — he's counted six thefts of walnuts and almond shipments in recent months — the thieves cut through a fence. "The walnuts were in three double-trailer sets ... apparently the suspect or suspects hooked up their own tractor to [it] and then drove it off through the fence and...