BitNinja has a greylist a blacklist and a whitelist. All three have an account level and a global level.
The IP lists differ in strength. In the list below you can see their order of precedence, from strong to weak, the account-level whitelist being the strongest:
Account-level whitelist
Account-level blacklist
Account-level greylist
Global whitelist
Essential list
Global blacklist
Global greylist
The account-level greylisting, blacklisting or whitelisting only takes effect on the servers under the account.
If an IP address gets greylisted due to an incident or manual listing ( account level ), after a certain amount of incidents, this IP will be globally greylisted.
If there are even more incidents generated by the IP address the Address will be globally blacklisted
IP addresses that are greylisted on the account level or globally can be delisted via CAPTCHA. This can be done by sending an email address to a mail server where the Ip is greylisted or by accessing one of the domains where the IP is greylisted and solving the CAPTCHA.
A blacklisted IP address can not be delisted via the CAPTCHA.
If an IP address gets greylisted at BitNinja, we keep logging the requests from the IP address until it is not delisted from the greylist. This means, the reason why the IP address got greylisted is not even close to the recent incident logs.
You can read more about the IP filter module and the CAPTCHA module.