Minneapolis, Minnesota -- When you hear a knock at the door, you don't expect it to be the authorities telling you, you've committed a crime.

Gary, thought extra money each month could help his family. So he found a work from home job online.

"It looked pretty legit as far as the company is concerned," Gary said.

He received packages, posted the items online and got a cut from each sale. The rest was wired to his employer. He thought it was working pretty well until he got a knock at the door from a postal inspector who told him he was using counterfeit postage, which is a federal crime.

"That was a complete shock," Gary said. "Turns out this company was not paying for the postage. In some way or another, I felt really, really bad – really bad."

He sent more than 500 packages over a year. He believed the company was legitimate because of its efficient systems.

"The criminal enterprise is becoming more and more organized and sophisticated to the level where they are actually running websites where these new re-shippers will login into the website. They will see all of the list of packages that they are expected to be getting in the next day or two days," Jeff Long, U.S. Postal Inspector said.

Gary was even getting a pay check. In most reshipping schemes, the victims never get paid.

"In 26 years of being an inspector – I have not come across one single instance of a legitimate reshipping case. It doesn't happen," Long said.

If you find a job online, do your homework. Check the BBB's website or with the state attorney general to see if there are any complaints about the company.