That would be seen as a greedy move. This forum was made to be a place for free discussion and for people to learn about cryptocurrencies. If people started seeing that they have to pay to be able to ask a question on a forum they would get discouraged. I guess i'm not ready for discussion because I wouldn't pay for registration. I'd move to free forums like reddit. Nobody is inviting spammers here. They are coming of their own will!
This will ruin the idea of a forum so to speak.
Not finding all, just the ones you can find.
You forget it's not against forum rules to farm/sell accounts or to have alts here. Charging $10000 or ~1BTC is more expensive than buying a legendary account outright (depending on account quality).
You don't need to find all to convince people to not do something, you just need to find "most" to show you're making some sort of impact to those who participate in this sort of thing.
-I was only using an example to explain my point.
Again this is why I think it's a bad one... that idea will bring more workload because these people will never come forward by their own to pay the forum.