DENVER (CBS4) – They claim they are IRS agents threatening you with arrest or court action if you don’t send them money immediately for back taxes. It’s a phone scam that’s been sweeping the nation. But when the scammers targeted Rachel Fitzsimmons of Denver, she fought back.

“I wanted to give them a taste of their own medicine,” said Fitzsimmons, a sales and marketing professional.

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When the scammers left her voicemail messages on consecutive days this month, telling her they were filing a lawsuit against her for failing to pay her taxes, Fitzsimmons said, “I was really scared. I never had someone say they were filing a lawsuit against me, especially the IRS.”

But after a little research, Fitzsimmons realized it was nothing more than a scam which the U.S. government says has swindled nearly 3,000 people out of $14 million so far. The scammers typically alter their caller ID number to make it appear they are calling from an IRS office and pose as IRS agents offering up badge numbers and identification numbers.

So Fitzsimmons called back and recorded the entire conversation then put it on YouTube, hoping it would help others avoid falling for the scam.

“Officer David Miller,” speaking in broken English, told Fitzsimmons she had made a “miscalculation … somehow you made a mistake in your tax filings” and said she needed to fork over $1,000 immediately or a warrant would be issued for her arrest.

The real IRS says they never make calls like this and if they need to get in touch with you, they will send a letter.

Midway through her conversation with the phony agent, Fitzsimmons surprised him.

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“I actually work for the IRS,” she claimed (she does not). “Do you realize you are taking money from innocent people?”

The scam artist immediately hung up.

“I was just like, how could he be doing this to so many Americans who work hard for their money? I’m just thinking, how could you do this to nice people?”

The IRS has received reports of more than 20,000 of these scam calls in the last 15 months. Locally, CBS4 has received numerous complaints from viewers getting the same type of scam calls as those received by Fitzsimmons.

Additional Resources

If you receive one of these calls, you are asked to report it to the Treasury Inspector General for Tax Administration at 1-800-366-4484.

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CBS4 Investigator Brian Maass has been with the station more than 30 years uncovering waste, fraud and corruption. Follow him on Twitter @Briancbs4.