Emma Taylor (Ashley Benson), a graduate student, moves to New York City for a fresh start after her recent break up with her boyfriend Alex. After getting settled into her new Brooklyn apartment, someone begins anonymously hacking all her electronic devices and watching her through the cameras. One day while attending college, Emma meets Michael (Matt McGorry), who asks her out. The two begin dating. However, one night Emma pleasures herself, after which she becomes suspicious after the hacker begins stealing private photos of her with Michael and sending her messages and videos pretending to be Michael. She confronts Michael who denies sending the messages, but Emma does not believe him and starts avoiding him.To relieve some stress, Emma and her best friend, Nicole, go clubbing. While they are out the hacker breaks into her apartment. She returns home drunk and passes out on her couch without knowing her hacker is out on her balcony. When she wakes up he is gone but doesn't pay attention as she goes into the bathroom to relieve herself. Michael comes over later that day to see how she is doing and to give her a cat so she is not so lonely. The two then reconcile about before and have sex. A little while later Michael calls her and tells her someone emailed him telling him to leave Emma alone. Emma freaks out and calls the cops who do nothing. She begins feeling isolated and depressed because there is nothing anyone can do about the situation.One day Emma comes home to find her apartment door unlocked. She walks in her home and finds her cat dead. She tries to call Michael and tell him the news. However, he never answers or calls back. Feeling more vulnerable than ever Emma spends the day wandering the city so she does not have to be home alone. She makes plans with Nicole to hang out at Emma's apartment later so she returns home.While waiting for Nicole, Emma and her mom video chat. During the middle of the chat Emma's power cuts off and she begins screaming. The hacker appears and begins attacking Emma while the chat with her mom is still going. Emma's screams abruptly stop and her mom calls the cops. The hacker then turns the laptop towards him and Emma's mom begins pleading with him to leave her alone. He shuts the laptop. After the credits roll the cops show up and begin looking for Emma who along with her hacker are nowhere to be found.