It's for your own good. It's a piece of ****!
Where to start...
1) The wires from the AC connector to the PCB board are almost as thin as Kynar wires. Mmm... Poor wires, also that would generate some heat and maybe stress/resistance.
2) The PCB is squeezed together inside this little plastic housing, which might suffer from heat issues if left over night
3) When I crack opened mine, the first thing I noticed was a big solder tin ball that fell out. Imagine what kind of madness that little chap could've done...
4) I noticed that the AC rail wires are squeezed onto the side of the charger, which could worn out the protection layer. On a related note, the wires are placed right beside a diode/resistor (can't remember what it was). Again, that's a potentionally dangerous issue, especially if the wires have a worn out protection.
Even though it seems to be in pristine conditions, don't use it. You're probably good to go if you strictly check its inners and solder on some fatter wires on the main AC rail.