Note: Lauda cannot return to the forum, even an imposter cannot use the account. The account was banned and the signed message was invalidated.
Lauda wasn't banned. He left the forum on his accord and said he was never coming back. I think the account was locked at his request, because from what I read he asked the community to tag any account bearing similar username, or if his account ever became active again.
Yeah, KingsDen's post there had me very confused for a second, because I don't recall Lauda's departure ending with a ban. Either way, the person who is Lauda certainly can return to the forum, even if it means using a new account.
Maybe I used the wrong word "banned", it could be said that Lauda was blocked on her request. I can say that the account Lauda would not be able to return to the forum as Lauda using same account. See this posy
My only
PGP-key has been compromised and revoked. All previous Bitcoin signed messages are invalid. As of this point there is no way to confirm ownership of Lauda.
-----BEGIN PGP PUBLIC KEY BLOCK-----
Comment: This is a revocation certificate
iHgEIBYIACAWIQQfLmKkVT7aaToRySNE4007Yzz06gUCX4ws7wIdAgAKCRBE4007
Yzz06oEdAP9Wj7TxqjBWerqkQR5KgMjE3aWrn7i1a11cCfXF0IEndAD/aGHi/H/G
OoVLKE4TeoDSIWHs7PHn1cml/xIpHSAeuwc=
=Il0J
-----END PGP PUBLIC KEY BLOCK-----
Thank you everyone in advance, quite the 9 lives that some Kitty had here.

It could be the reason Cyrus said in Bitcointalk YouTube show quiz section, that Lauda among Vod, Tman and others is the only person that cannot reappear in the forum.