What is the deal on intercepting these guns? If the government was offering $50 why cannot I stand out there offering $60 and pick up the gems.
Different jurisdictions will have different rules, but what are the basic notions behind laws to thwart private sales?
It all depends on the state.
In most states private sales are legal.
The people organizing these events do not like private sales, because it destroys the narrative “guns bad, turn them in”.
Many, many people have gone and purchased guns at these events.
But there are a few states where every sale has to go through a dealer. Those include California, New Jersey and Massachusetts.