Can you plug a powered USB hub into a cinema display USB port?

[millerrh]

I did this and my monitor's LED light was still on even when the power was disconnected! I unpluged the USB hub, and the light went off. Is this bad for the monitor to have "multiple power sources?"

 

[MisterMe]

Your monitor is an unpowered hub. USB devices which are powered by the bus don't work.

 

[millerrh]

Your monitor is an unpowered hub. USB devices which are powered by the bus don't work.

That wasn't exactly my question. I have a powered USB hub (it plugs into the wall). I have that hub plugged into one of the USB ports on my monitor. This way I only need to plug in the one USB plug into my laptop that comes from the monitor cable bundle.

However, when I turned off all the power and unplugged the power cables to my monitor, the LED was still on. As soon as I took out the USB plug from the hub, the light turned off. So the power coming from the USB hub was somehow powering my monitor LED to light up.

This seemed like it could be a bad thing to me to have power being input into my monitor from anyplace other than the power cord.