Robots are smart enough and have the ability to clean up after they murder somebody. People in movies can hear the soundtracks. Clothing shields laser beams. Watching somebody's head explode will not invoke fear. Security robots are armed with lasers powerful enough to explode a person's head.
Pillows can explode.
Security robots are armed with C4. Safe air ducts are extremely frightening. Robots have blood. Robots can read our minds. Molotov cocktails are extremely ineffective when used against fast moving robots.