A Langley, B.C., family says police are finally taking their complaints about a computer hacker seriously after a fake 911 call tricked police into surrounding their house with an emergency response team.

But the incident is not the first of its kind. It appears to be part of a serious prank call trend dubbed swatting —  tricking police to send out a SWAT or emergency response team to an unsuspecting home by using techniques known as spoofing to disguise the origin of the 911 call.

Louise Gray says her family has been constantly harassed by a hacker for a year and a half after her son posted a video to YouTube. Since then their phone numbers, addresses and emails have ended up all over the web, she says.

Then on Monday, Gray alleges, the hacker used her son's computer accounts to call police through the family's computer, saying he had killed several people and was holding more hostages at their home.

When Gray opened her door she was surrounded by the police emergency response team.

"There was the SWAT team all along the neighbour's yard pointing guns at me and telling me to put my hands up," she said.

Police have seized the Grays' computers to try to find the elusive hacker. But Gray says when she went to police when the harassment first began the RCMP ignored her. 

"I'm frustrated, but I am relieved they are looking at it now. It's too bad it took this for them to take this seriously, because I am sure we are not the only people this has happened to," she said.

Swatting on the rise

Cybercrime experts confirm the Langley case was actually the second such incident of swatting in recent days.

A well-known internet crime expert had her house surrounded by the SWAT team in New Jersey on Sunday after someone made a fake 911 call.

In 2008, a man from the state of Washington was sentenced to three years in a California prison and fined $14,000 for swatting.

According to Peter Cassidy, a member of the Anti Phishing Working Group, a non-profit organization studying internet crime, swatting is becoming more and more common.

"Someone picks a target they want to abuse and they call the local police," says Cassidy.

The caller poses as a hostage taker, claims to have guns, gives a home address, all the while hoping police will respond with a SWAT raid at the unsuspecting target's home.

In order to persuade police that the call is real, the swatters use a simple trick called ID spoofing to hide the true origin of the calls.

In the Langley case, police said the call appeared to come from a cell phone with a California area code.

But Cassidy says swatters can just as easily make it appear the call comes from a target's home by using one of several spoofing companies on the internet offering a free service allowing callers to choose whatever number they want to show up on the caller ID.

Cassidy says police used to be able to trace the call through the handful of major phone companies who held a virtual monopoly. But he says the industry has now become so fragmented it's become very difficult to trace the origin of such calls.