sorry for the downvote. I have no fight with the group I don't like the people posting anonymously how would we verify reputation?
No need to be sorry.
As you may know, the people behind Anonymous are not interested in growing a reputation at all. They have their cyber-political goals and they try to achieve them as a collective, not as a set of reputable individuals.
But I see your point: How would I (as the sole administrator of the account) ensure that I give posting permissions to "the group".
As an alternative, I may as well publish a private key for it instead and let people use it for whatever reason.
That is a horrible idea. Mostly because you give control over the voting power of your account as well.