15-year-old Hunter Gelinas of Naples, Fla., learned all about it firsthand when a SWAT -- or special weapons and tactics -- team stormed his house.
Swatters had hacked his X-Box account and used the console's Internet connection to send a message to authorities.
"They were saying that Hunter had been stabbed and the parents and other people being held hostage at the house," his mother, Dale Ann Gelinas, said.
Hunter recalls: "I come out of my room and they've got their guns pointed at me and stuff … I was like, 'Oh my God, I'm going to die.'"
Swatters are usually young computer hackers working alone or in groups, according to the team of FBI officials who profile them. They choose their victims carefully – though, at times, it is completely random.
Swatting has spread throughout the United States and Canada in recent months.
"Once you catch a swatter or a group that is committing these crimes, they are usually responsible for multiple swatting incidents," said Kevin Kolbye, the assistant special agent in charge of the FBI's Dallas office, which headed the first federal swatting case in 2007.
Kolbye has been piecing together what appeared to be isolated swatting cases around the country since 2004.
Swatters aren't motivated by money, he said.
"Some of the motivation for swatting has been revenge against their victims or ego or bragging rights," Kolbye said. "There has been very little monetary gains in swatting."
Crank Calls Cost Money
The FBI is cracking down on the practice. One of their biggest arrests was Matthew Weigman, a blind 19-year-old hacker from Massachusetts who is now serving 11 years in federal prison for swatting.
The FBI's biggest concern is that, one day, the criminal crank calls will turn deadly.
"They [SWAT officers] are responding to a hostage or a possible homicide situation," Kolbye said. "They are very aware that they are going into a very dangerous situation. They are in a heightened state, the safety's off and their finger is close to the trigger."
In addition to the possible danger to the victims, there is the financial cost.
The FBI says each swatting incident costs law enforcement an average of $10,000 in resources.
One group of swatters recently prosecuted by the FBI was responsible for 300 calls in 17 states.
Swatters can face federal charges of conspiracy, carrying a maximum penalty of five years in prison, and fraud, with a maximum of 20 years.
ABC News' Reshma Kirpalani contributed to this story.