False reports of active shooters that put Villanova University in Philadelphia and the University of Tennessee at Chattanooga on lockdown and saw law enforcement swarming over campuses last week were likely perpetrated by an online swatting group called “Purgatory,

A terrifying text message sent students running for cover, barricading themselves in bathrooms and knocking over chairs in the frantic rush to hide from the active shooter reported on their university campuses.

Such hoax calls, often referred to as “swatting,” have becoming increasingly frequent in the U.S. in recent years.