A fantasy football competition in Philadelphia got out of hand, with federal and foreign authorities launching an investigation into it after a disgruntled player falsely accused a fellow participant of intending to carry out violent attacks.

Prosecutors with the Department of Justice announced on Wednesday that 25-year-old Matthew Gabriel pleaded guilty to two counts of interstate and foreign communication of threats.

Authorities said a disagreement between Gabriel and another member of a fantasy football online chat group allegedly led to him telling police that the member, who he knew was going to study abroad in Europe in August 2023, was planning a bombing and mass shooting in Norway.

Gabriel wrote that a fellow fantasy football player was "headed around Oslo and has a shooting planned with multiple people on his side involved. They plan to take as many as they can at a concert and then head to a department store," according to prosecutors.

"I just can’t have random people dying on my conscience," he wrote to authorities.

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A fantasy football competition in Philadelphia got out of hand, with federal authorities launching an investigation into it after a player falsely accused a fellow participant of intending to carry out violent attacks. (Tim Heitman / Imagn Images)

Prosecutors said that they took the tip seriously and that U.S. and Norwegian investigators spent "hundreds of man-hours reacting to and investigating the threatened mass shooting over the course of a five-day period."

Gabriel's ruse did not last, with the FBI interviewing him and the 25-year-old admitting that the "tip" was a lie.

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Further investigation into the international ruse revealed that Gabriel emailed the University of Iowa with a similar threat earlier in the year.

In the second threat, Gabriel alleged that the same fantasy football player was threatening to "blow up the school," which Gabriel knew was untrue, prosecutors said.

U.S. Attorney Jacqueline Romero warned fantasy football players to not participate in similar "extremely disruptive" hoaxes. (AP Photo / Jose Luis Magan / File)

Gabriel was released on Tuesday on a $25,000 bond and is scheduled to be sentenced in January. If found guilty, he faces a maximum penalty of five years in federal prison and a $250,000 fine.

U.S. Attorney Jacqueline C. Romero warned other fantasy football players to not participate in similar "extremely disruptive" hoaxes.

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"While already being prosecuted for one hoax threat spurred by, of all things, his fantasy football league, Matthew Gabriel inexplicably decided to send another," Romero said. "His actions were extremely disruptive and consumed significant law enforcement resources on two continents, diverting them from actual incidents and investigations. Hoax threats aren’t a joke or protected speech, they’re a crime. 

"My advice to keyboard warriors who’d like to avoid federal charges: always think of the potential consequences, before you hit ‘post’ or ‘send.’"