I have a idea of getting rid of people from clan threads that is not from your clan /ally.
Block them from entering the clan thread (yes, thread).
But you may enable them in such threads like Recruitment Thread.

It's like an on/off button to allow anyone to post in that thread.
So random people can't post crap there.
But the forums have to implement a new ally system, which might be hard :
To allow that Clan to post in your Clan thread.

Agreed?

That's a moderation issue. Not really worth creating an ally system just to restrict people's posting privileges, when simple bans can do the trick. We do provide private boards for official clans.

Private Boards.
Won't it be better to make it much more simpler rather than having to type in the password ?
It will be tiring if a untrustworthy clan member to spread out the password, issues will be that the clan have to restart the password and finding out who did it.
So even if the password spreads, others still can't post there using the method I said.

Once you have entered the password, there will be no need for you to do any password reenters anymore.

There's more to clans than who can post where. Even if someone does invade, so what... it's not like it's the end of the world. Also thanks to cookies you don't actually have to type the password every time to get into private boards. Either way there's no easy way to override vbulletins forum permissions to grant people access to parts of the forums.

I just noticed you're in an official clan which already has a private board, and moderators who can delete unwanted posts in the public board. So there are already several existing solutions to something which is only a problem on rare occasions.

Invading without permission that is.

Oh well... this idea won't keep up long.
Closing thread.