First, you need login to your Group Twitter Account at Twitter.com and mark your account as "Protected." For more info,
this Twitter Support page
. Please note, that with Protected accounts, you will have to manually approve each follower
of your account.
Second, by default, all GroupTweet dashboards are defaulted to "semi-private." This means that anyone you
share your GroupTweet invite link with can sign up and start Tweeting from your account. If you want to make sure you have total control
over who can access your GroupTweet dashboard, switch your GroupTweet privacy settings to "Private" which will require you to have
to manually approve each contributor that signs up with your invitation link.
If you desire complete privacy, in addition to
contributors Tweeting from your private dashboard, the only remote
GroupTweet option you should enable is the Direct Message "Tweeting Method". This means contributors can also participate by
sending a Direct Message from their personal accounts (either public or private) to the GroupTweet account. These incoming
private messages will be converted into Tweets from the private GroupTweet account for only approved followers to see.