Apple CEO Tim Cook has said he's "deeply offended" by fresh allegations of poor working conditions in its suppliers' Chinese factories. Contractors hired by Apple to assemble its latest products have been exposed before, and while the firm has tried to be more proactive in recent years, a new BBC investigation suggests the same problems still persist. Undercover reporters hired at Pegatron factories discovered an exhausted workforce regularly falling asleep at the production line. Twelve hour shifts are common, which means employees often clock over 60 hours on the factory floor each week -- well above China's 44-hour limit, but still possibly legal given the country permits 36 hours of overtime each month.