I'm not interested in buying any accounts. Just curious, where did you get this accounts? Are this hacked accounts? bought? or it is yours originally?

I saw some sellers advertising they have a way to prove they own the account.

I can imagine that if an account with significant notoriety has been hacked and/or sold, the original owner could verify his identity with the board and reclaim it.

All accounts is not bought or hacked. I can verify the accounts is mine.

What rule would that be? Stupid people enable scammers. Use escrow and you won't get scammed. And you don't need to buy an account to scam when you can just create a new one. Should we ban the creation or new accounts as well?

What could be an ownership proof for accounts created from scratch? The forum doesn't even send an confirmation email.

 You can resell an account, but there is no guarantee that the reseller didn't bought an hacked account.

A screen capture can help?

Do you have official stats on those figures or have you just made them up to suit your argument? I think it's safe to say the vast majority of accounts are sold solely for signature campaigns and you don't need to buy an account to scam as you can do that just fine with a newbie account. A little bit of feedback shouldn't mean you can toss all judgement out of the window and throw your money around willy-nilly (though sold accounts rarely have any positive feedback - especially not trusted feedback). Use escrow and you should be fine. The reasoning behind the staff letting accounts be bought or sold is because they can't really stop it and letting it happen out in the open lets everyone know that it does indeed happen.

If you have more than 1 account, I thought sig campaigne is better way to generate more money for you.