Hi! Recently a family of 6 renewed their green card while residing in Canada. They' ve been given a green card about 10 years ago and now renewied it. What they did was just showed a fake US potsal address of their friend and got their cards. They have never lived in the US and don't have any tax ids or even never file a tax. The funny thing is that US immigration officers didn't pull their backround data and didn't find out that they've been living outisde the country for more that 10 years. They travel once in a while on their Canadain passports so they border officers never find any glitch. How can I report this fraud and make sure that this case be investigated in future?

What did they do to you, to make you want to report them ? Why do you care they have a green card?

There is no way to report to make sure they will be investigated. They may be if you report them, or they may not care to spend the time on something that would not be a national security issue.