It’s difficult to care about the demise of characters in a horror movie when they’re all already brain-dead. That’s the moral of the stultifyingly stupid, distinctly unfrightening “Unfriended,” a gimmicky ghost story with a cyberspace theme.

The movie, directed without style by Levan Gabriadze, portrays things entirely on a single computer screen the camera never leaves. Its owner is Blaire Lily (Shelly Henning), who’s initially shown watching online footage of the suicide exactly one year earlier of her classmate Laura Barns (Heather Sossaman), along with the humiliating post of Laura drunk at a party that had gone viral and led her to kill herself. But Blaire is soon joined in a group chat by her boyfriend Mitch (Moses Storm) and their pals Jess (Renee Olstead), Adam (Will Peltz) and Ken (Jacob Wysocki). Unfortunately some anonymous hacker is horning in on their conversation, sending messages that purport to be from the deceased Laura. They suspect that another classmate, Val (Courtney Halverson) is pranking them, but once she’s added to the chat, it appears they were wrong.

Things go from bad to worse—not just for the characters, but the audience as well—when the hacker begins accusing the nattering quintet of responsibility for Laura’s death in posting horrible things about her. She also sows discord among them by posting embarrassing things that they presume come from the others. But then she strikes one of them down, presumably—as an informative website suggests—by taking possession of the victim and compelling her to commit suicide. Another will soon follow, leaving four glued to their screens and forced to play a game of “Never Have I” that reveals terrible secrets about them all and results in each meeting a well-deserved fate, though devotees of teen slasher movies may be disappointed that the gore level s surprisingly low.

You have to hand it to Gabriadze and screenwriters Nelson Greaves and Parker Laramie for finding a cheap but innovative way of tweaking the musty found footage formula to make it seem distinctive. But cinematographer Adam Sidman wasn’t able to do anything to minimize the essential dullness of having a stationary camera focus on a computer screen for nearly ninety minutes. Frankly it’s as boring to watch Blaire’s journeys through Skype, Google, YouTube, Facebook, Wikipedia and Chatroulette as one’s own surfing usually proves to be. It seems that computer screens are just dull cinematic devices, whatever data you fill them with—even if it’s a guy killing himself with a blender.

But to be fair, the entire process would be less irritating if the characters weren’t such obnoxious jerks and the acting were better than amateur-night quality. As it is, the cast should perhaps be given credit for persuading us that they’re just a bunch of dumb high school types chattering away about their past online cruelties. But that doesn’t make them any more sufferable, and it certainly doesn’t persuade you to sympathize with their plight.

In fact, the only bright spot about “Unfriended” is that it will force its target teen audience to read the messages its characters post to one another. It’s almost like getting them to watch a picture with subtitles. Unfortunately, the posts are the same sort of drivel that likely viewers probably send to one another in real life. Early on in the movie Blaire consults a chat site that warns against responding to e-mails from the dead. What’s really needed is a warning against going to a movie about jerks who do.