 -- The malicious prank of "swatting" -- calling in false emergencies that send swarms of heavily armed cops to a school or home -- is often perpetrated by X-Box gamers who occasionally hijack peoples' Twitter or Facebook accounts and refuse to release them unless the victims make a swatting call, according to an affidavit filed in federal court.

The affidavit cites the case of Matthew Tollis, of Wethersfield, Connecticut, who is accused of taking part in seven swatting calls. Tollis was allegedly part of a group that threatened to bomb the University of Connecticut, attack the home of an individual in Connecticut, create false threats to school across the country, and in one ghoulish call told police that a man with an assault rifle was headed to the new Sandy Hook Elementary School, the scene of a notorious massacre of staff and first graders.

Tollis claimed to federal investigators that he began taking part in the swatting calls after he was targeted online by hackers who "doxed" him, a tactic of posting online all of his personal information, including Social Security numbers and passwords, and "pizza bombing" him, sending large numbers of pizzas to his house which he then had to pay for, according to the federal document.

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“Tollis explained that he began to look for ways to protect himself and his family from online abuse,” FBI investigators wrote in the federal affidavit obtained by ABC News. He told the FBI he joined a group of gamers who called themselves “TeAM Crucifix or Die” (TCOD) because “it would discourage others from bullying him.”

The group's membership allegedly includes gamers who live in the United Kingdom and use names like Verified, Jordy and Declaws, the affidavit states. Tollis used the name Hxrbor, according to the document.

Tollis, 21, was arrested Sept. 3, for his alleged role in the April 3 swatting call that claimed there was a bomb at the University of Connecticut. He is charged with three counts connected to the UConn incident as well as three counts of federal conspiracy and aiding and abetting.

Tollis' attorney Jeremy Weingast had no comment on Friday before Tollis was due in federal court.

When he was interviewed by investigators, Tollis said he was involved in a total of seven swatting calls, including calls to a high school in Texas, two in New Jersey and one in Florida, the document states. There were also threats made against Boston University and the Boston Convention & Exhibition Center. Tollis denied making the calls himself, "but admitted that he had laughed in the background of the calls,” the affidavit states.

He also told investigator he knew about a host of others that the group allegedly perpetrated, including the call regarding Sandy Hook Elementary School, the document states.

“I was scared of being their next target so I did not inform the Authorities of their Actions,” Tollis wrote in the statement, according to the affidavit. “I stood by and watched as resources were wasted for hoax calls. I did so out of fear and regret associating myself with these people."

The federal affidavit, filed Sept. 9 in U.S. District Court in New Haven, Conn., said "the group primarily consists of Microsoft X-Box players or gamers." It described how a victim of doxing may have their personal identity details publicized or have their Twitter account taken over with the hackers "extorting individuals seeking to regain control of their Twitter accounting by requiring the individual to, among other things, send nude photos of themselves or calling the police to report an incident that would require specialized units like SWAT or the bomb squad to respond (swatting,)" the affidavit states.

Microsoft, which created the Xbox, said that they do not comment on specific cases but are "committed" to trying to prevent gamers from using their consoles for illegal activity.

"Any criminal activity occurring over Xbox Live is a violation of our Terms of Use. We have a dedicated enforcement team who supports efforts of law enforcement officials in the pursuit of potentially criminal incidents occurring over the service," a Microsoft spokesperson told ABC News.

Brian Krebs is a cybersecurity expert who has been swatted several times and said swatters carry out the pranks "for fun," but said not only do the pranks divert vital resources that may be needed elsewhere, it is very dangerous.

"The problem is these police forces when they show up, they show up heavily armed. The police force that showed up at my home wasn't a SWAT team, but had automatic weapons," said Krebs, who runs a cybersecurity site.

"These situations can get very intense very quickly," he said. "These guys come in and they're pumped. They're ready to respond to a high energy intense situation and their fingers are on the trigger. This is going to be a bad situation at some point when they kick in a door and somebody is defending their home."

Tollis, who could not be reached for comment, is scheduled to appear in federal court Friday and in state court later this month.

FBI has an open ongoing investigation and additional arrests are anticipated.