Humans

Humans are systems. We are machines. The most complicated machines ever. But machines, nonetheless. And, like all machines, we can be operated if the right buttons are pushed, the right levers pulled. So how do you work another machine? Well, you figure out their buttons and levers, and the proper sequences and BAM, you can control other people. It's not even an art as much as it is a science. You become the proprietor of someone elses body, and the world is yours for the taking.