America's crime hunters, the FBI, are on a worldwide computer-crime chase that has brought them to New Zealand.
They are looking for a hacker who has headed up a global group using other people's computers as a vehicle for cyber crime.
Since June last year, the group is thought to have attacked more than a million computers, ripping off victims to the tune of nearly $20 million.
Spamming is big business and even though most people just hit delete, the small percentage who do respond make big bucks for cyber criminals.
The FBI probe has seen a series of arrests around the world.
"Once your computer is part of a botnet then it's essentially compromised and somebody else you don't know is controlling it and so that means they could be accessing any information that you're transmitting on your computer... that would potentially include your banking information," says Martin Cocker from Netsafe.
Authorities in New Zealand, working in collaboration with the FBI Philadelphia office, conducted a search this week at the residence of an individual who goes by the cyber ID of akill.
Akill is believed to be the ringleader of an elite international botnet coding group that is being blamed for infecting more than a million computers, making money for organised crime.
Netsafe says it is likely New Zealand's bot-herder, the criminal accessing other people's PCs, is part of an online crime ring.
"There are places on the internet where you go and you say this is the service that I can deliver and you'll get picked up by a crime gang or something to do that service and so quite often these will be international connections between the different parts of a crime syndicate," says Cocker.
A person becomes part of a botnet when a piece of malicious software is put onto their computer - typically when an attachment is opened - and especially when computer security isn't up to scratch.
And once the botherders have their cyberhands firmly inside your PC it's really hard to tell.
"I don't think people should be afraid of the internet or afraid of these kind of things but people should definitely be aware of it," says Cocker.
An American FBI agent is still in New Zealand.
