When Florida police got a call from a man who said he shot four people at rapper Lil Wayne's house this month, they responded as they are trained to.
Heavily armed, flanked in body armor and accompanied by sniffer dogs, officers surrounded the Miami mansion after the alleged shooter told the 911 dispatch: "I'm killing whoever else I see..."
But police found no shooter at the house, and no victims. Lil Wayne was not there either.
The rapper was the target of a "swatting" prank, a phenomenon gaining popularity in the United States and creating public safety risks and budget strains for law enforcement.
The stunt -- a modern-day and much more serious version of a prank call -- involves a call to emergency services claiming a crisis.
When police arrive, the alarmed victim is often greeted by angry bangs at the door from screaming officers with cocked guns.
Special weapons and tactics (SWAT) units are usually dispatched -- which the term swatting comes from -- because they are trained to deal with serious emergencies swatters typically falsely report, such as hostage taking, mass shootings, bomb threats and domestic violence.
Following the false alarm at Lil Wayne's mansion, Miami police said on Twitter: "Unfortunately this appears to be a 'Swatting' call. No victims /no injuries /no subject at 94 LaGorce."
Police are obliged to respond to emergency calls, but say such pranks are a waste of resources.
"Fortunately in terms of no one hurt yes. Unfortunate in the waste of resources for a hoax that we have to treat seriously," Miami Police tweeted.
Lil Wayne is not the only celebrity swatting victim.
Famous Hollywood prankster, Ashton Kutcher, host of the hoax show "Punk'd," has been swatted, along with Justin Bieber, Rihanna, P. Diddy, Justin Timberlake, Tom Cruise and Miley Cyrus.
Swatters have also hit politicians, journalists and schools.
- Live-stream swatting -
The phenomenon of swatting was first reported to the Federal Bureau of Investigation in 2008, and has steadily gained popularity since.
Officials estimate about 400 swattings occur every year, but many no longer report incidents to prevent copycat acts and to avoid giving swatters publicity.
The hoax is popular in the online gaming community, where swatters target online rivals who are live-streaming a game. When police arrive, the stunt is broadcast in real-time.
Swatting videos show victims at their computers when they are interrupted by loud bangs at the door followed by heavily armed police storming their homes.
Perpetrators target online rivals and access their addresses by hacking their computers.
Police consider the act a dangerous crime, and say swatting is a serious public safety issue.
"The swatting practice is extremely dangerous and places first responders and citizens in harm's way," the FBI said in a statement.
"It is a serious crime, and one that has potentially dangerous consequences."
Beyond being a waste of resources, police say swatting creates major risks.
Some hapless victims were carrying objects that could be mistaken for a weapon. Others grabbed a real gun, mistaking law enforcement for intruders
Police are at risk too -- in one incident an officer was injured in a car accident while responding to a swatting hoax.
"It's only a matter of time before somebody gets seriously injured as a result of one of these incidents," the FBI said.
- Seeking tough laws -
But tracking perpetrators is tough, as callers use software to disguise the call origin or place the calls from untraceable Internet sites.
Though there is no federal swatting legislation in place, punishment can be tough for swatters who are caught.
In 2009, 19-year-old Matthew Weigman was sentenced to 11 years in prison for orchestrating several swattings. The blind phone hacker who was a member of a swatting ring had been making the fake calls to police for five years.
Some politicians are pushing for tougher laws to deal with the crime.
California Congressman Ted Lieu introduced legislation in his state that was adopted in 2014, forcing convicted swatters to pay for costs related to fake calls, which can be as much as $10,000.
Lieu, himself a victim of swatting, said the bill protects the public and prevents police resources from being wasted.
Despite moves to strengthen punishments, the phenomenon continues to gain momentum, both on US soil and abroad.
Last week, French television host Enora Malagre was a victim of swatting when a man called police claiming he stabbed her and threatened to shoot at police.