Most of the unlicensed gear I've seen has been less-expensive items such as charge/sync cables, AC chargers, and battery packs--items where, because of their lower cost, Apple's licensing fee is more difficult to absorb into the cost of the product. Most speakers, higher-end docks, and other "premium" gear I've seen is licensed, likely because their higher prices make it easier to cover the costs.
How does your phone or tablet know it's connected to an unlicensed accessory? Licensing the Lightning connector gets a vendor more than just a badge for its packaging. It also provides access to special authentication circuitry inside the connector itself. If that circuitry isn't present--as it isn't on unlicensed gear--iOS 7 throws up the error (and, in some cases, it appears, prevents the accessory from functioning). Some companies have attempted to reverse-engineer the circuitry, some more successfully than others, but the risk to buying unlicensed gear is now greater than before.
If you've got an unlicensed charging accessory that no longer works under iOS 7, a Reddit user offers a workaround that, in our testing, sometimes works. However, use it with caution: There's no way to tell if you've got a high-quality, safe accessory that just isn't licensed, or if the manufacturer also cut corners in other places, resulting in a dangerous product.
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