The difference is that those cables only carry low voltage DC. To get line voltage AC on them you'd need a short inside the power brick bridging from one side o

The difference is that those cables only carry low voltage DC. To get line voltage AC on them you'd need a short inside the power brick bridging from one side of the rectifier to the other. Apple is very careful to isolate those two sides. Knockoff chargers, not so much. See this teardown comparing a genuine Macbook charger with a counterfeit version: http://www.righto.com/2016/03/counterfeit-macbook-charger-teardown.html http://www.righto.com/2016/03/counterfeit-macbook-charger-te... High voltage and low voltage should be separated by a safety gap of at least 4mm (to simplify the UL's creepage and clearance rules). On the circuit board below, the high voltage input section is at the bottom and the low voltage output section is at the top. On the right half of the board, the two sections are separated by a large gap, which is good. On the left, there should be a gap (bridged by the optoisolator). Unfortunately, traces and components pass through this area making the gap dangerously small, under 1 mm. Any moisture or loose solder could bridge this gap sending high voltage to the output.