Yup, very true beckdg, thats why i put a lot of emphasis on a smartphone wall charger or even a cheap little USB power hub instead of putting it into a USB port. USB 3 "technically" can handle up to 1 amp on the USB rail, but the problem with that is one of power supplies, can the motherboard rail pump out that full 1 amp without cutting back on the supply to the motherboard? Too risky...
I had it plugged into a USB 2 port at the front of the case, all my USB 3 ports are at the back of the tower.