Wikipedia
Pranknet, also known as Prank University, is an infamous Canadian-based anonymous prank calling virtual community responsible for damage to hotels and fast food restaurants of more than $60,000 as well as multiple instances of telephone harassment. It was founded by a man who later referred to himself as "Dex" (alleged to be a Canadian man named Tariq Malik). The group has been linked to nearly 60 separate incidents.
Posing as authority figures, such as fire alarm company representatives and hotel front-desk/corporate managers, Pranknet participants called unsuspecting employees and customers in the United States and tricked them into damaging property, setting off fire sprinklers, breaking out windows, and other humiliating acts such as disrobing and consumption of human urine. Pranknet members can listen in real-time and discuss the progress together in a private chat room.
In 2009, a wave of the pranks across the United States prompted internal alerts by Choice Hotels, as well as advisories by the Orange County, Florida Sheriff's office, and others. At that time, law enforcement officials from a number of jurisdictions and the Federal Bureau of Investigation began investigating the various incidents as well as the identity of "Dex".