"Assassination Nation" peaks early, with a funny prologue full of helpful trigger warnings about impending sex, violence, racism, and threats to the "fragile male ego."

It accurately heralds the anarchy to follow, a "Heathers" meets "The Purge" meets Russ Meyer free-for-all that takes elements of the Salem witch trials and transposes them to the age of the internet. That's a lot to take on, and there are diminishing returns by the time the movie reaches its bloody conclusion.

The story takes place in a town called Salem (palm trees suggest it's not New England) where a quartet of 18-year-old female friends attend school by day and hedonistic parties by night. Writer-director Sam Levinson shows us the proceedings as an iPhone might, creating an atmosphere of casual surveillance. And what we see often resembles how social media recapitulates events — filtered and distorted, with subjects who have internalized the idea that their privacy has been sacrificed to terms of service.

But secrets do persist. Lily (Odessa Young) gets sexts from a person named "Daddy" and responds with titillating selfies. Her friend Bex (Hari Neff), a young trans woman, is hooking up with an in-the-closet football star. The mayor has secrets, too, and so may the high school principal. All are revealed when a hacker siphons up the town's digital secrets and posts them online. There is an eruption of paranoia and anger, and the four young women become the focus of the town's rage and wrath.

There's a barely circumstantial logic to this, but that's part of Levinson's point. The town's anger needs an outlet and a target, and young women are just as likely to be irrationally/conveniently singled out today as they were hundreds of years ago, in that other Salem.

Levinson, though, is not exactly T.S. Eliot. Lily gets a few decent monologues about the problems facing women in a time of dangerously mixed messages, but the movie's journey to empowerment takes a long detour through the kind of leering exploitation it argues against.

The film means to strike a blow for women, but there must be a way to do that without the spectacle of one girl bashing another girl's head with a baseball bat. There is a repulsive scene of Lily having an encounter with "Daddy," a flimsy and odious setup to a spasm of score-settling violence. Other story threads disappear entirely (a subplot involving the principal dissolves without explanation).

National politics get name-checked (chants to lock people up; talk about taking the town back), and American flags fly over depraved masked-mob carnage, in the glib manner of a "Purge" sequel.