The spec for USB 2.0 cables says max length of 5 meters. Having said that, you can get away with longer cables if you are just using it for power. The problem when you use longer cables is either voltage drop or bad shielding. Sounds like yours is bad shielding, so you are inducing noise into the cable.
Change the cable for something shorter and/or pickup a higher quality cable. There are lots of cheaply made USB cables available. They have smaller wire size and questionable soldering. Higher quality cables will have 24 ga. wire and be able to carry 2 amps, which is close to what is needed to run the indoor cams.