The phrase "mindless zombies" refers to people who are behaving or acting without thinking or reasoning, like zombies in movies or stories. They are not making conscious decisions or using their intelligence. Full definition
Genetic mutations caused by the virus have turned many of those remaining into mindless zombies with dangerous mutant powers. (gamergeddon.com)
You're wasting your breath here... surrounded by a bunch of mindless zombies who can't differentiate between having access to something (Gee, you had me fooled if you think it's hard to find contraceptives in any town in this country!) (religion.blogs.cnn.com)
because people analyze situations instead of going forward like mindless zombies doesn't mean we're unhappy. (religion.blogs.cnn.com)