"It's not just guns that are slipping over the border and into generalcirculation, " said Hugh Pope, a senior analyst with the International Crisis Group in Turkey.
However, with the old federal assault weapons ban having expired in 2004, there were already millions of such weapons in circulation at the time then Texas Solicitor General Cruz filed his amicus curiae brief.
According to the US General Accounting Office, two-thirds of pennies are out of circulation, with many of them disappearing almost the moment they reach the public.