Hello guys, I'm interested in your input here.. I was lying in bed watching a tv show on my iPad mini while it was plugged in charging and I noticed that when I rubbed the back (along the edge opposite the attached Smart Cover) with one finger, it felt like the metal was vibrating as I rubbed it. if I then touched somewhere else on the back while rubbing, the vibrating seemed to stop, and likewise if I unplugged the lightning cable the vibrating stopped and it felt like regular aluminium again... I would be interested to see if anyone else has experienced or has any thoughts on this?