I thought this was kinda interesting... There are blacklists in USPSA and IDPA. We have a blacklist in the region. People on the list cannot shoot a competition...
https://github.com/jonstokes/shooter...er/proposal.md
"The basic idea is to have gun owners vouch for other gun owners’ fitness to handle and use guns, and to incentivize those people to evaluate each other carefully by forcing them to have skin in the game. In this way, we can build up and maintain networks of licensed shooters whose experience of gun ownership is relatively frictionless—no arbitrary rules about barrel length or whether an item is a “stock” or an “arm brace”, and no extra paperwork or waiting periods—while denying access to firearms to individuals who can’t join such a network and remain a member in good standing."