Basically it draws power from the computer and sends it back!
This will efficiently kill your hardware if you have done nothing to protect your USB port from this. One can only speculate why the computing world has so little interest in securing the USB port but Apple has secured its hardware from this so that it cannot receive back the damaging power stream.
The Hong Kong guys have made the industry aware of this issue one year ago so now they are releasing the product for security testing purposes.
To avoid the disaster you can buy an adapter that will prevent the power from flowing back to your hardware.
This will probably not prevent the stealing of data so you have to use an USB condom on your mobile devices too.
Basically those Hong Kong guys are creating the problem and double the sales by creating the solution. That makes their noble motives questionable, but they are right about it being a problem and that some dishonest crooks would have done it sooner or later anyway.
Also the computer industry has done nothing about it despite fair warnings.
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