Prevent people from registering via your comment moderation blacklist.
Yes! They are the exact same list, they use the same fields and they update the same data. The only reason I put it there was I felt having an all-in-one place to get the data would be better.
No. Since WordPress doesn't list rejected comments (your blacklist goes to a blackhole), I didn't bother with trying to do that here. If enough people think it's a need, I may consider it.
This plugin no longer uses Stop Forum Spam. If you need that feature, please use Stop Spammer Registrations instead. They did it way better.
Surprise! Yes! If you're using multisite, instead of pulling from the comment blacklist (which is per site), you have a separate list off Network Admin -> Settings. This is because you only want to have the network admins determining who can register on the network.
Yes. Caveat: I have not fully tested with Multisite and BuddyPress, so I want to warn you that it doesn't always give the pretty error message. It does ban hammer them, though, so ... yay?
You can block by domain by entering @example.com, but you cannot block all .com emails. This is because of the crossover between the Blacklist and the Ban List. Say, for example, you want to block the word cookie from being said in comments. If you did that, Ban Hammer would block firstname.lastname@example.org too!
I'm not sure. I've gotten a handful of reports from people where it's not working, and for the life of me, I'm stumped. So far, it looks like Zend and/or eAccelerator aren't agreeing with this. If it's failing, please post on the wp.org forums with your server specs (PHP info, server type, etc) and any plugins you're running.