Fans of the Los Angeles Dodgers, the Oakland A's, New York Yankees, or NBC's Today may have noticed something unsettling occurring over the weekend. With the release of Paramount Pictures' new horror film Smile just around the corner, strange people have started popping up on public broadcasts with an unflinching, incredibly sinister-looking grin. The terrifying, potentially possessed individuals made the rounds on social media with baseball media company Jomboy Media sharing clips of their exploits among the crowds in Oakland and LA. Erik Davis of Fandango also compiled several sightings including one in the crowd behind Al Roker and Hoda Kotb.

The various folks are donning Smile shirts, confirming that this is one big, clever viral marketing campaign. It goes beyond simply spotting people in public, however, as there's also an official site where fans can report smiles they see in the wild and a number they can call or text to give information on the smiles. On top of it all, fans can show off their own possessed faces with a new Snapchat filter that contorts their normal grins into a sinister smile. It's all in good fun and very terrifying to come across in a public setting.

In the context of the film, you absolutely don't want to see those smiles though. It stars Sosie Bacon as Dr. Rose Cotter, a psychiatrist left shaken after seeing one of her patients horrifically commit suicide. The woman claimed to see an entity smiling at her from the shadows and, after witnessing her gruesome death, Rose starts hallucinating too. Faced with an overwhelming terror, she's in a race against time to investigate other patients with similar experiences and confront her own past in an effort to save herself from the entity.

Caitlin Stasey smiling creepily at the camera in 'Smile.'

RELATED: The Final Trailer for 'Smile' is Here to Inspire Your Nightmares

Smile features a solid cast with Kyle Gallner, Jessie T. Usher, Robin Weigert (The Undying), Kal Penn, and Rob Morgan all joining Bacon. It's the debut feature for Parker Finn, based on his short film Laura Hasn't Slept, which took home the SXSW Film Festival's special jury recognition Midnight Award. Like the short before it, Smile made its debut on the festival circuit, earning solid overall reviews from critics after appearing at Fantastic Fest on September 22. Originally slated to appear on Paramount+, the film did well enough at test screenings to force Paramount's hand into giving it a full theatrical release. If anything, the viral campaign is only a further vote of confidence for the film, especially with how much attention it brought.

Check out the shots and clips of the various real-life smilers below. Smile arrives in theaters on September 29.

See the final trailer for the film below.