http://www.jsonline.com/news/milwaukee/63459407.html Federal law also prohibits anyone from selling guns to felons and others prohibited from owning a gun including a straw buyer. But there have been no such cases filed in Milwaukee in at least five years. Prosecutors said that's because they are such hard cases to prove.
Straw buy cases aren't easy and often depend on ATF agents getting a confession.
The straw buyers issue is what the subthread is discussing. Those buyers are not felons before being busted. There are efforts to make it a felony so that they become one, too.