Yes, I have. It's very sad. I was told by an instructor at the Ontario Police College that he is frequently confronted by young aspiring police trainees who believe and place their trust in the long-gun registry. They believe what they see on the computer.
In one case, Constable Valérie Gignac, a constable in Laval, Quebec, checked the registry on December 14, 2005, before she confronted a trouble call. When she knocked on the door of this man's apartment, he shot and killed her through the door with an unregistered rifle, a rifle that the long-gun registry did not know was at this residence, a rifle that the man was prohibited from owning but that he nevertheless had. Obviously, trusting the long-gun registry can get people killed.
As I've shown in my statistics, there are exceptionally few cases of long guns being found in homicide cases. We have 4,800 homicides, with almost 1,500 firearms homicides in this time period, and 73 long guns registered. That's it. How can a long-gun registry have any impact on anything?