How/Why this Happens?

There's a spike buster beside my comp; It powers my computer and various devices like speaker/ etc.,
I have a webcam thats connected to USB.
whenever i plug in/out any device in the spike buster.
the Webcam LEDs 'Glow n OFF' (LED's used as Night Light)
The LED's are operated using a switch. But even when the switch is OFF.
It Blinks as said above.

Cheap webcam?

quite cheap...
but still i paid for it!!
But will it happen so?

Not sure you're not describing the problem you're having very well, not sure exactly what's going on.