[qb45]

Just as a side note, some of the cheapest USB chargers have 1mm or so of clearance between high voltage and low voltage circuits, which places them one small accident away from the "mains to USB adapter cable" territory.

[Dylan16807]

I know, but that's not a cable. You need more diligence when buying transformers, but a wire with a plug shouldn't be able to do unexpected damage.