For those unaware, most developed nations around the world have ended the process of lobotomy. Not just because it was horrible but because it proved to cause more issues than it solved. The process of lobotomy was to make an incision into the prefrontal lobe on the brain. This involved often removing small parts of the lobe completely.
The frontal lobe where lobotomies were done is quite important to how humans function and operate overall. This section of the brain affects your personality, expression, decision making, cognitive behavior, as well as social behavior. If someone were to manipulate and control people who were lobotomized, imagine the ramifications of that. These people could easily come across to others as practically dead, setting up something of a real zombie apocalypse.