If you have two devices with female USB A ports that both provide power via said ports, connecting them with male-male cable ~~will create a short circut. Best case scenario: a current protecting fuse breaks the circuit. Worst case: both processors on both motherboards are dead.~~ Better not think you can connect two computers with that evil thing. That's why type B connector exists, it's about the same size, but it never connects to a port that provides power.