It's illegal, but because firearms are so hilariously ubiquitous, there is effectively no standard of ownership or storage, and law enforcement has inadequate tools to tackle gun tracing by design, there is ample opportunity for a prohibited person to unlawfully obtain a gun in the US. Made even more laugable by the open, legal marketing of products like the P80, which are ending up in police evidence lockups across the country.

The gun culture in America is inherently anti-social and anti-establishment, so rules and laws cannot just be lightly suggested and expected that they be followed. People need to consistently go to prison and permanently lose their gun rights for their fuckups to start changing things.