All of my gun-control friends and family are making the most effective hay with this issue. Can you explain the HAPPA thing in more detail or give a link?
Your friends shouldn't be making any hay with this. VA Tech was a gun free campus. They took a student to court last year for legally carrying with a CCL on campus and won. The VA legislature made a law (or the VA courts ruled, I don't know which) that the university could ban guns on campus. They were quite proud and happy about it. They made sure no one could defend themselves.
Ask them if they could wave a wand and make all guns in the U.S. disappear and make them illegal how many weeks would it take for the black market to bring a million guns back in? And who would have them all then? Only criminals and they would know that no one BUT criminals had them.
I don't know if that would faze them but that's what I think of asking them. There is also the issue of not hospitalizing the insane as we used to. I don't know the details of that either but it was about 30 or 40 years ago and it regarded their civil rights not to be deprived of liberty against their will. That goes hand-in-hand with the privacy laws to prevent the courts and society from protecting ourselves from lunatics.