Jordan Mathewson was live streaming Wednesday morning while playing a video game called Counterstrike. In the game, he plays a gunman on a mission to take down imaginary terrorists.
But the fantasy quickly became a reality, as Mathewson himself became a target of police, CBS News correspondent Michelle Miller reports.
SWAT teams burst into his office, their weapons drawn and aimed at the gamer. Police ordered Mathewson to the ground and placed him in handcuffs.
Local schools and businesses were on lockdown for more than an hour. After finding no threat, police realized the 911 call was a prank known as "swatting."
Swatting is when someone reports a fake emergency, causing police SWAT teams to respond to the scene.
Law enforcement says there's nothing funny about it.
"As you can, tell there's a lot of resources here and a lot of taxpayer dollars going to work here - it's incredibly dangerous" said Littleton, Colorado Police Chief, Doug Stephens.
Colorado had another swatting incident this April, when a 15-year-old boy targeted a girl after she insulted him in a chat room.
Swatters have also targeted Hollywood celebrities, including Justin Beiber, Ashton Kutscher and the Kardashians.
"This isn't just one car that goes to this, it may be 10 cars, it may be 20 cars," said Los Angeles Police Chief Charlie Beck. "This is not a game, you know, this is real life. You are taking real resources away from people that need them."
Littleton police are still investigating.