Those who are completely opposed to any training requirement, need to think very long, about what is being said here, and the opinions that are being presented. There are unsafe gun-handlers out there.
If we are concerned about gun handling behavior around us, we should speak up, respectfully, gently and make sure people understand what they are doing that is unsafe, and why its unsafe! In most cases, doing this privately, one on one, is the best way to do it, so long as our attitude is one of being helpful, not confrontational. People are less defensive if they do not feel they are being ganged up on, or embarrassed in front of a group.