[Logician]

Kathy by default the hack is not suggested for large communities for 2 reasons:
1- In large communities with a lot of members hack will match many users with same IP or ISP or password so wouldnt give you a good idea as to whom the new user might be.
2- Hack does not only compare IPs in the user database but also in the post database to give more accurate results and if you have a large database (user or posts or both) it would take a very long time to match new registerar's IP in the database which will result in a slowdown in register process.

So it's not good for you as it is.

But I guess it can be tweaked so that it will only compare IPs of banned members and warn you if a "potential" banned member re-registers or even better put him in a special usergroup (like moderated) if the hack decides new user is likely a "banned member". :glasses: