The Gun Control Act of 1968, a US Federal law, prohibits convicted felons from possessing firearms. The problem is that more and more non-violent crimes are now classified as felonies, which means that an ever increasing portion of the population is now prohibited from possessing guns:
Once upon a time, felonies were limited to serious and primarily violent offenses, such as murder, rape, robbery, kidnapping, serious battery, home invasion, etc. However this has changed. Poaching lobsters, improperly importing artwork, and sending spam email are now felonies in various states. These activities should certainly be punished, however they are a far cry from the (mostly violent) conduct that was traditionally punished as felonies. Other laws seem almost laughable, such as the West Virginia law that makes it a felony to teach a bear to wrestle.
Because more and more crimes are now felonies, there is an increasing segment of the population that is prohibited from possessing guns. This is worrisome both for the person convicted of a non-violent felony, as well as the country’s law abiding gun owners. A person who is deprived of the right to keep and bear arms for self defense is more vulnerable to criminals, and more vulnerable to police abuses. The country’s law abiding gun owners are also imperiled in the long run, as having fewer and fewer people who own guns will lead to fewer and fewer people who support gun rights. Indeed, the overwhelming majority of the anti gun people I’ve known have no personal experience with using guns. I can also speak from first hand experience on that point, having grown up in an anti gun family, where I was not exposed to ideas of gun rights or the benefits of gun ownership.
Have a look at Lautenberg, too. There are so many holes in that piece of dung. All it takes is to yell in public and you're a prohibited person.