The more I think about it, the more I like a shadow-ban type of system. The question is, how to implement it properly so it doesn't prevent people from wanting to register on Bitcointalk and only keeps the bad guys away? We know how resourceful they can be when they smell blood and an opportunity to scam and abuse. They can easily pretend to be regular newbies wanting to before part of the community, only to show their real faces once their shadow-bans are lifted.

You missed an important 3-letter word there. Not! As long as it's not broken...