In the scheme, six separate rings of scam artists, most in India, call people in the United States, Canada, Australia and elsewhere, identify themselves as working for reputable companies and ask the victim to check his or her computer. The consumers are then told their computer has a virus that can be removed for a fee of $49 to $450.

FTC Chairman Jon Leibowitz estimated that the scams had netted tens of millions of dollars.

The FTC froze the U.S. assets of scam artists, had their websites taken down and convinced U.S. phone carriers to shut down services that allowed them to operate from India using U.S. telephone numbers.

Five of the six groups telephoned consumers and claimed to be from legitimate companies such as Microsoft or Dell, while the sixth advertised through Google.

There were 2,400 victims of these particular scams in the United States, although the FTC has received 40,000 complaints about this type of fraud.

"This is a very widespread scam affecting hundreds of thousands of U.S. consumers," said David Vladeck, head of the FTC's Bureau of Consumer Protection.

(Reporting By Diane Bartz; Editing by Maureen Bavdek)

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