Back in June, we discovered Apple implemented a warning in iOS 7 Beta builds to caution people against using non-certified Lightning cables, many of which contain cracked authentication chips.
Specifically, connecting an accessory to an iOS 7 Beta device through a non-certified Lightning cable produced a prompt saying “This cable or accessory is not certified and may not work reliably with this iPhone”.
It seems the company has thrown down the gauntlet to unauthorized accessory makers over the use of unapproved Lightning cables because folks have confirmed that the shipping version of iOS 7 now in fact blocks such cables, preventing them from actually charging your iPhone...