It is a federal law and occasionally they prosecute the most egregious examples, but I've heard from many gun dealers that when they suspect a straw purchase and report it, the ATF follows up maybe 1% of the time.
Jeeze, they even went after a former police officer? Not saying former cops should get a pass, but you’d think they’d try and make an example out of someone involved in a criminal operation.
The ATF/DOJ loves to make examples out of people even when the case is pretty weak.