Suggestion: Unlisted-only mode

[saschanaz]

It would be:

1. Any follows not in UnlistedTwitterAccounts will be disallowed (Something like Moderation:TwitterAccountsBlackListing=*
2. Boosts/quotes from UnlistedTwitterAccounts will be imported as Unlisted, assuming Unlisted accounts interact only with other accounts that match requirements to be Unlisted. (Some brand accounts still interact with random people, though)
3. Perhaps some way to request new Unlisted accounts, except contacting the admins.