With all these instances of the system dropping the ball, why on earth should we clamor for, or even accept, any new laws under the guise of "common sense."
This has long been a gripe of mine. When I was a dealer, I had several instances in which I shut down a suspect sale, called the ATF, and was told it wasn't their responsibility to deal with it. I actually had a file with copies of the 4473, a note with the names and numbers of the agents with whom I'd spoken, and a copy of the video of the incident just in case something happened.
During the post-Newtown feeding frenzy, there were congressional hearings on background checks. The Baltimore chief of police testified about how we needed more background checks and bans. A senator pointed out that there were only 52 prosecutions for violations of the Brady Act between 1998 and 2013 and asked why his department wasn't more aggressive in pursuing that. His response was, "those are paper crimes. We don't have time to go after those."
Remember, this isn't about public safety. It's about being seen passing laws.