Well, that could have been bad. I found this dangling from my Macbook Pro when I came home. It had a USB warning about turning off the port because something was drawing too much power. Gee, I wonder what that could have been?

Luckily, the USB ports both work fine because of that feature. Now I just go to the Genius Bar with this and a smile, say “smoke” and “fire” a couple of times and see what happens.