problematic play on lackey

Do we have a solution for people that ragequit on lackey?
Or give up when they feel they lost?that does not happen on live tables but is an issue online. Besides that it is always the same people who fuck up games.
I am sad to suggest this but should we start a blacklist?

Maybe you can start building a black list and start games only with "certified" players. Associating an actual vekn with nicknames could help "empower" people.